SciBlogs

Posts Tagged Review

I’m Certain That I Can Certainly be Wrong or Confidence and Memory, Is one a Good Measure of the Other? Darcy Cowan Mar 05

No Comments

A man is the sum of his memories, you know, a Time Lord even more so.

The Doctor, in “The Five Doctors”

ResearchBlogging.org
We all know that our memories can’t always be trusted, time and life tends to erode the confidence we have in our memories. At least that is the case for normal memories. We also tend to have special memories that seem to be burned into our brains, events in our lives that hold such significance that it feels like we are in some sense still experiencing the moment the memory represents. Such memories are described as being “flashbulb memories” as if at that moment as sort of metaphysical flash went off and recorded every detail of an event vividly in our consciousness.

This “flashbulb” effect allows us to confidently recall these events days, weeks or even years later. Memories such as this may be unique to each individual but there are commonly cited examples of shared flashbulb memories such as where a person was and what they were doing when they heard about the events of 9/11. In fact this event was used in an experiment to test the accuracy of this type of memory. At Duke University on September 12th 2001, 54 students recorded their memories of hearing about the incident as well as a recent everyday event by answering a series of questions about the events. Then either 1, 6 or 32 weeks later they answered another questionnaire and this was used to evaluate the confidence and consistency of the memories.

Surprisingly there was no difference in the consistency of memory recall for the flashbulb memory compared to the everyday memory but the flashbulb memory continued to be reported with a high degree of confidence while confidence in the everyday memory decreased. This implies that while we can be very confident in the details of a memory this is no guarantee of their accuracy. In fact other studies between confidence and accuracy of recall (for example in eye witness reports of crimes) shows the same lack of correlation between how confident we are and how accurately our recall matches events.

With regard to confidence in memories hypnosis is often put forward as a means of increasing the reliability of recall (even featuring on Mythbusters). There is evidence however that what actually happens is the hypnosis increases the confidence of the recall but is not effective at increasing the accuracy of the information gained through this process.

Finally, as a little reward for getting this far that is modestly related to this subject, here’s an interesting little test that is meant to measure your risk IQ based on your confidence in the answers to certain questions rather than on the answers themselves. (as previously blogged on by Alison over on Bioblog). So go take the test and feel free to report back your score.

References:

Talarico, J., & Rubin, D. (2003). Confidence, Not Consistency, Characterizes Flashbulb Memories Psychological Science, 14 (5), 455-461 DOI: 10.1111/1467-9280.02453
Smith, V., Kassin, S., & Ellsworth, P. (1989). Eyewitness accuracy and confidence: Within- versus between-subjects correlations. Journal of Applied Psychology, 74 (2), 356-359 DOI: 10.1037/0021-9010.74.2.356
Green, J., & Lynn, S. (2005). Hypnosis versus relaxation: accuracy and confidence in dating international news events Applied Cognitive Psychology, 19 (6), 679-691 DOI: 10.1002/acp.1133

Related articles by Zemanta
Reblog this post [with Zemanta]

Filed under: Psychological, Sciblogs, Science, skepticism Tagged: Cognitive science, Duke University, Five Doctors, Intelligence quotient, memory, psychology, Review, Science, Science and Society, Social Sciences, Time Lord, Witness

Intelligence, Monogamy and Journalistic Licence Darcy Cowan Mar 02

3 Comments

ResearchBlogging.org
Last week news came out about a study linking intelligence with liberal attitudes and atheistic beliefs, oh and in men an increased tendency for monogamy. Today I read the NZ Herald‘s short take on the study, a semi-chauvinistic piece pointing out how we evolved intelligent men can think our way to monogamy while those sexually immoral women can’t. I felt just a little dirty reading it. Ok, perhaps it isn’t really that bad but having being familiar with the study before reading the story that’s how it stuck me.

The full published study is locked behind Social Psychology Quarterly’s pay wall but the lead author, evolutionary psychologist Satoshi Kanazawa, rather nicely provides copies of his papers on his own website. I like him already. The paper, rather provocatively called “Why Liberals and Atheists Are More Intelligent.”, discusses a concept Kanazawa calls the Savanna-IQ Interaction Hypothesis. Essentially this states that our behaviours were shaped by our evolutionary past and that intelligence may allow us to adapt these behaviours and introduce new behaviours that are “evolutionarily novel”. In this scenario general intelligence (IQ) evolved as a mechanism by which we could adapt to novel situations that our genes alone had not equipped us to deal with.

To investigate this principle three types of evolutionarily novel behaviours/values were examined to determine if there was any correlation with intelligence. To wit the behaviours looked at were liberalism, atheism and monogamy. Throughout the paper the relation of monogamy to men as being evolutionarily novel specifically excludes women, not because women’s behaviour in this regard cannot be moderated by intelligence but because monogamy is not a novel concept for women. In our evolutionary past women (according to the hypothesis) would always have been more monogamous and so this would be classed as an evolutionarily familiar strategy which does not require higher intelligence to change thus the prediction that intelligence would not be correlated with greater monogamy in women where it would be in men.

In fact multiple studies have already shown that across cultures women tend to be more monogamous so what this study implies is that men have to be more intelligent (in order to overcome our stupid genes) just to get on a par with women. Frankly though this is the least interesting part of the study. More fascinating (though also more potentially inflammatory) is the association of intelligence with liberal and atheistic modes of thought. For the purposes of the study Kanazawa simplified the definition of liberalism to:

“the genuine concern for the welfare of genetically unrelated others and the willingness to contribute larger proportions of private resources for the welfare of such others.”

Stated in this way the concept actually looks a little unfamiliar to me as well as my hypothetical ancestor. But if I consider it for a while I can squint my eyes and see it as encompassing most of those values I generally lump together as being liberal. In any case Kanazawa’s argument boils down to the conjecture that our ancestors would not have lived in societies in which we would have been surrounded by large numbers of unrelated individuals such as we are now. In this case they would not have had much incentive to develop behaviours which valued unrelated strangers as much as ourselves, in fact I could see this sort of behaviour as actually being detrimental.

This may explain why liberal people are more intelligent than their conservative counterparts but it does not address the question as to why intelligence might lead to the adoption of these principles, why aren’t we just more intelligent conservatives? What’s so great about being liberal?

The question might be slightly clearer in the case of atheistic beliefs as those that espouse this point of view tend to make it into an argument about truth. Certainly there must be an advantage to knowing the truth about the world around us but how this might relate to a more or less abstract truth such as the existence or absence of a deity is not obvious. I would be interested to see if intelligence is more highly correlated with believing more concrete truths about the world independent of actual scientific training (which presupposes that the beliefs formed about the world in this fashion are approaching trueness).

Fun as these topics maybe to speculate about it’s difficult to say how much these sorts of studies tell us about the evolutionary origins of particular behaviours as I have seen in comments to this study elsewhere it smacks of just so stories. I’m not an evolutionary psychologist so I’d rather stay away from interpretation in this vein but perhaps we would do well to take any conclusions with a grain of salt, especially if those conclusions are what we want to hear.

Reference:
Kanazawa, S. (2010). Why Liberals and Atheists Are More Intelligent Social Psychology Quarterly DOI: 10.1177/0190272510361602

Related articles by Zemanta
Reblog this post [with Zemanta]

Filed under: Psychological, Religion, Sciblogs, Science Tagged: Atheism, evolution, Intelligence, Intelligence quotient, Liberalism, Monogamy, psychology, Review, Satoshi Kanazawa, Science, Science and Society

Extinction Vortex of DOOM Darcy Cowan Feb 10

No Comments

How is it that I’ve never heard this cool phrase before? Well not so cool for the species it applies to but still, someone was having a good brain day when that one was coined. The idea of an extinction vortex has been around for almost 25 years but I’m only just hearing about it now (maybe I was asleep, I mean uh sick, that day in biology class). As the name hints an extinction vortex describes factors affecting declining species that make extinction for that species almost inevitable.

An overview of the structure of DNA.
Image via Wikipedia

The paper that brought this phenomenon to my attention is eye-catching named “Trapped in the extinction vortex? Strong genetic effects in a declining vertebrate population“, published by researchers at the University of Gothenburg, Sweden. The paper looks at the genetic factors influencing the decline of an endangered shorebird the southern dunlin, specifically the effect of reduction of variation in the species due to inbreeding.

The most significant thing about this paper for lay readers is that the primary contributing factors pushing endangered species toward extinction need to be understood in order to put appropriate counter strategies into place. In this case the effects of inbreeding, likely due to reduced population size, have weakened the species and made it more difficult to produce healthy offspring. Protection of the nests and increasing the available habitat for the species did not significantly  impact the species’ steady decline. This implies that conservation minded programs should be aware that once a species is in decline multiple strategies, including reproductive approaches, may be required to halt the decline and bring the species back to a stable population.

With currently over six thousand threatened species recognised this would seem to be an important lesson to learn. If conservation efforts are to succeed then at risk populations must be fully evaluated to determine the approach that has the best chance. As noted by the study authors, genetic damage may be hardest to see (via casual observation) when the effects are most severe: when the damage is such that embryos perish before viable individuals can be born.

I can’t sum up better than the study authors themselves so I’ll let their own words wrap things up:

“We have shown that a declining population of a long-lived, endangered vertebrate suffers from substantial negative genetic effects. Our results highlight that ignoring genetics may underestimate the extinction risk of natural populations and thus lead to inappropriate conservation measures”

Related articles by Zemanta
Reblog this post [with Zemanta]

Filed under: Sciblogs, Science Tagged: Biology, Endangered species, Environment, Environment and Ecology, Population, Population size, Review, Science, Species, Sweden, University of Gothenburg

Smoking Bans and the Effect of Health Warnings Darcy Cowan Jan 21

No Comments

In the world today there is an increasing focus on the negative aspects of smoking and a concerted attempt to reduce the presence of smoking in society. Given the harmful effects of this addiction on not only the active smoker but those around them this seems like a prudent move. Two of the approaches with the goal of minimising public exposure to cigarette smoke are the banning of smoking in businesses and public places and the addition of more strenuous warning labels on the cigarettes themselves.

Both of these tactics have been used in New Zealand with varying levels of acceptance (and success). Smoking bans draw the criticism that individual freedoms are being curtailed. This may be a legitimate point but conceptually it is no different than government enforcement of wearing seatbelts while driving on public roads. The aim is to reduce the risk of harm to the public. The real question in each case is whether the intervention is effective in it’s goals.

Addressing this question two studies last year looked at each of these methods, the first I will look at is a meta-analysis (with the concomitant problems those have, that’s another story) of the effect of smoking bans on the hospital admissions of acute myocardial infarction (that’s a heart attack to you and me). The analysis found that smoking bans were associated with an average reduction of heart attacks by 17%.

For each year a ban was in place it was accompanied by a reduction of the incidence rate ratio (the number of new cases per unit of population eg 10 cases per 100,000 people) of 26%. This indicates that the longer a ban is in force the fewer people who will be affected by heart attacks. Looks like an effective strategy to me, 17% is nothing to be sneezed at when it is individual lives you are considering. Depending on individual risk factors the chance of death in the 30 days after a heart attack can be up to 16%.

An editorial discussing these findings in more depth (in the Journal of the American College of Cardiology, the journal this study was published in) can be found Here and is a good read.

The second study focused on the how well explicit (i.e. emphasising death) cigarette pack warnings encouraged smokers to quit. Specifically it looked at smokers for whom the act of smoking formed part of the basis for their self-esteem. Subjects undertook a questionnaire that evaluated whether smoking was tied to their self esteem using statements like ‘‘Smoking allows me to feel valued by others,” and ‘‘Smoking allows me to feel worthy.” (as well as negative versions). The subjects rated how much they agreed with the statements and this was used to determine the smoking-based self esteem for each subject.

Participants were then shown pictures of cigarette packs that either had mortality related warnings (e.g. ‘‘Smoking leads to deadly lung cancer.”) or more moral or self esteem related warnings (e.g. ‘‘Smoking brings you and the people around you severe damage” and ‘‘Smoking makes you unattractive”). After a delay to allow the warnings to be filtered out of conscious awareness the subjects were asked a further series of questions to assess the effect of the warnings (e.g. ‘‘Do you intend to smoke more or less in the future?” ‘‘Do you intend to quit smoking in the future?”).

Subjects for whom smoking formed part of the basis for their self esteem actually increased their likelihood of smoking in response to warnings emphasising mortality. For these people it was the self image warnings that were most effective. Unfortunately is seems that the opposite is true for individuals that do not consider smoking to be an important factor of their self esteem so a one size fits all approach would probably not be effective. The study authors suggest that specific populations could have warnings tailored to be most effective depending on the relevance smoking has to the group identity (e.g. “young smokers who want to impress their peers.”).

This result may be applicable to other areas where minimising harm is the goal, such as drink driving campaigns.

In summary, despite any reservations regarding the form that inducements to stop smoking take it seems that the benefits are indeed worth the attempt. Also, as I often point out, the real world is more nuanced and complicated than we would generally like it to be, more effort may be required to identify sub-groups that respond most to different strategies but this also looks to be worth trying.

Related articles by Zemanta
Reblog this post [with Zemanta]

Posted in Medicine, Psychological, Sciblogs, Science Tagged: American College of Cardiology, Cigarette, health, Health and Medicine, Lung cancer, Myocardial infarction, New Zealand, Review, Science, Science and Society, smoking, Smoking ban, Tobacco smoking

I Trust You More if I Think You Think I’m Attractive. Darcy Cowan Jan 13

No Comments

As always things aren’t as simple as headlines suggest and the headlines of science based blogs are no exception. Of course people don’t actually go around assessing how attractive other people think they are and modifying their behaviour accordingly. These psychological biases and effects go on below conscious awareness but the point is that they do happen. Previous studies have shown that humans will tend to treat attractive people better and trust them more than unattractive people. Recent research has looked at whether this increase in trust can work both ways, that people will be behave more trustingly the more attractive they are.

While not immediately obvious it would make sense for this to be the case, consider that trust is a sort of social contract and we have an implicit understanding of the levels of trust individuals in our lives deserve. If greater trust is afforded to one segment of the population based on a scalable factor such as attractiveness then a reciprocal increase in trust based on this would tend to develop in order for this social contract not to break down. In addition to attractiveness people have also shown to act more altruistically and trustingly towards others when they know they are being observed. This also makes sense, we seem to have a high sensitivity to how we are perceived by others and for good reason, how we are perceived affects how we are treated.

In this study subjects participated in an economic trust game, in this game the first player is given an amount of money, this player can then choose to give a second player a proportion of this money (an act of trust), the second player then has the amount he or she received multiplied by a factor (say three) and can then choose how much money to give back to the first player. Each player then keeps the money they have left in their pool at the end. In this way the amount of trust shown by the first player can influence the amount of money they receive back, a highly trusting person may give a large proportion of their money with the expectation of receiving an even larger amount back.

Participants in this game tend to give more money if they know they are being watched, or even if there are simply pictures of eyes visible to them (tapping into the social aspect of our behaviour). In this variation the participants were told that they were visible to the other player and their behaviour was then matched with how attractive they were, as determined by a panel of raters looking at photographs of the participants. The subjects’ estimation of their own attractiveness was also gathered and showed a positive correlation with the external rating (ie if a participant considered themselves attractive then other people were likely to as well).

The findings showed that in general the more attractive the participant was the more trusting their behaviour, if they thought the other player could see them. How the results were correlated also supports the contention at the start of this post, that this is not a conscious process. The researchers found that if they controlled for the external evaluation of attractiveness then the estimation of self attractiveness did not seem to correlate well with increased trust. The implication here is that this is a learned behaviour based on how they were treated by others in the past.

This is not to say that good looking people are always deserving of trust but it’s nice to know that, at least in this one instance, trusting behaviour can beget more trusting behaviour down the line. I find that a very optimistic result.

Posted in Psychological, Sciblogs, Science Tagged: attractiveness, Review, Science, Science and Society, social behaviour, Trust

Hands, Eyes and Uses for Bricks Darcy Cowan Dec 28

3 Comments

Are you Right, Left or mix-handed? Haven’t heard of mix-handedness? Current thinking in neurology and psychology seems to be leaning towards describing handedness as a function of the degree of preference for one hand or the other. For some tasks you may use your right hand, others your left, it is the amount or preference you show that will determine what handedness you are. Not sure now? This page has a simple test that aims to determine hand preference by asking about simple tasks and which hand you prefer to use.

The test involves thinking about tasks (such as writing and drawing) and deciding which hand you prefer to use.Each answer is given a score for each hand your handedness is then given a score using the formula: (Right – Left) / (Right + Left). A pure Left hander will score -1.0, conversely +1.0 indicates pure right handedness, intermediate scores show mix handedness with a preference one way or the other. One thing to note here though, a score of 0 does not necessarily indicate ambidexterity.

This approach may indicate how well the two hemispheres of your brain communicate with strong handedness correlating with less communication and mix handedness with more. So how well are your hemispheres getting along?

This concept of communication between hemispheres is also being implicated in more abstract capabilities such as creativity. A recent study (very well summarised Here and Scientific American’s 60 Second Science podcast) looked at whether creativity can be increased in individuals who performed an exercise designed to increase cross-hemisphere communication. The exercise involved having the study participants move their eyes back and forth horizontally for 30 seconds. This activity likely increases the amount of hemisphere cross talk due to the fact that for each eye the right side of the visual field is processed on the right side of the brain and the left field on the left, this is represented diagrammatically Here (this can lead to a fascinating pathology called Hemispatial Neglect where a patient acts as if the left side of the world simply does not exist, not relevant here but too interesting not to include).

So moving your eyes back and forth means that each side must communicate a little more while forming a coherent whole for the visual field. This extra communication may then carry over to other tasks, that was the hypothesis. The measuring of creativity would seem to be a tough call, in this case participants were asked to come up with as many different uses for mundane objects (like bricks) as they could, participants were regarded as more creative when they came up with more categories of use and uses not thought of by other participants (originality).

The study found that the exercise did have an effect but that the strength of the effect was determined by strong handed or mix handedness. Strong handers had a creativity boost for 6-9 minutes (depending on the type of creativity, originality or more categories of use). If you are a mix hander then there is no benefit from the exercise, but don’t be worried, you are more creative than the strong handers in the first place. The increase of the strong handers performance really only seems to bring them up to the mix handers level.

Perhaps then, if you favour one hand much more than the other and you need a quick increase in creativity, you could do worse than this simple eye exercise. For once science has come up with an easy answer.

Posted in Psychological, Sciblogs, Science Tagged: brain science, Creativity, Research, Review, Science

Disgust or Anger? Darcy Cowan Oct 21

No Comments

The ability to recognise the emotional states of those around us is a very useful tool which allows us to act appropriately in social situations. If this ability is impaired then it could lead to inappropriate reactions when dealing with others, this in turn could land us in hot water. An impairment like this has been suggested to explain the behaviour of delinquents, though it is unlikely to be a sole cause of antisocial behaviour.

A study published recently lends support to this hypothesis, published last month in the journal of  Child and Adolescent Psychiatry and Mental Health (or CAPMH for short, catchy) the study looked at 24 Japanese young adults that were serving time in correction facilities (in Japan). Simply put the researchers compared these so-called delinquents with a control batch of young people (matched for age and gender), in the ability to correctly match an emotion to a facial expression. Six basic emotions were represented with 8 different pictures each, so participants had to match a total of 48 pictures.

The emotions covered were anger, disgust, fear, happiness, sadness, and surprise, the prediction was that the incarcerated subjects would have difficulty interpreting some facial expressions and that this difficulty would skew the subjects towards misidentifying expressions as anger. This in fact did happen, the delinquent subjects actually identified disgust as anger more than the control group.

This interesting result is lessened in it’s impact somewhat due to the fact that the control group also made this mistake a large percentage of the time. This predilection in the delinquents however is an insight into how certain personalities might perceive some social situations as being more hostile than they really are. These personalities are also marked by being quick to anger and experiencing more intense anger than others so recognising how this occurs can be useful information in diffusing these situations and possibly diagnosis of individuals who might otherwise be labelled as simply “difficult”.

Tim Roth from the TV show <a href=

Posted in Sciblogs, Science Tagged: emotion, expression, facial recognition, psychiatry, psychology, Research, Review, Science and Society

Natural Health Expo(sed)? Darcy Cowan Oct 15

3 Comments

Driving around Hamilton the past few weeks I couldn’t help but notice the signs sprinkled around the city for the “Natural Health Expo” which is to take place here this week end. As I perused the website for this event yesterday I was disturbed by the large number of anti-scientific “treatments” that will be showcased. Like my co-blogger Grant who has already posted on this, I was troubled by the amount of misinformation that will be leveled directly at consumers.

As I was pondering how to answer the bewildering array of AltMed that will be promoted I checked my email and found a great little article just published in Chiropractic & Osteopathy (made available through the open access publisher BioMed Central).

The paper, “Why do ineffective treatments seem helpful? A brief review” written by Steve E Hartman, looks at how practitioners and patients can fool themselves into thinking that ineffective medical interventions actually work. An excellent example of Evidence Based Medicine 101, Steve covers the cognitive biases that hinder our ability to draw logical conclusions in the medical sphere such as the Post Hoc, Ergo Propter Hoc logical fallacy, confirmation bias and cognitive dissonance. Also covered are explanations of how it can seem that a treatment has been directly responsible for improvement in a patient’s condition when it may not  have been.

The paper touches on disease natural history, which simply refers to how a particular malady might be expected to progress without treatment. Self limiting diseases such as colds, headaches and fatigue can be expected to get better on their own . If a patient is taking a treatment at the time, the treatment (rather than their own immune system) might erroneously be given the credit.

This combined with the overlapping arenas of the placebo effect and regression to the mean can be a powerful confounding factor when treatments are not being considered in light of scientifically controlled settings. The placebo effect is referred to frequently in common culture but regression to the mean is a less well known entity for the layman. Steven does a good job of explaining the concept, essentially people experience a variety of different intensities in their symptoms. Also they will tend to seek medical help when the symptoms become severe, knowing that the severity of the symptoms will tend to cluster about a mean value it is likely that whether treatment is sought or not the patient’s condition will tend to get better.

Thus the patient will feel relief and attribute that relief to what ever modality they are using at the time. Practitioners are not immune to these effects either and will in their practice see time and again that patients are getting better after their pet therapy is applied. In which case they will feel justified in proclaiming it works in the absence of confirming studies (or even in the face of disconfirming evidence).

The one aspect that I felt was missing from the paper, although it may have been obliquely implied, is the role of prior plausibility in evaluating treatments. Many modalities that will be on offer at the Natural Health expo are not only unusual they fly in the face of currently understood science. Scientific plausibility is our compass, without it we can become lost in the wilderness of fanciful ideas without any method of discerning the way forward. This concept is what separates Science Based Medicine from simply Evidence Based Medicine. The former takes the plausibility of a treatment into account when deciding the threshold of evidence needed before it can be considered effective. The later only measures outcomes and so is less able to distinguish true effects from chance outcomes.

Consider the following scenario: I claim to be able to influence the outcomes of coin tosses by virtue of what I had for breakfast on a particular day. If I have eggs then tails with predominate, lettuce produces more heads. Now without considering the plausibility of the setup we could run a trial, perform statistical analysis and find that my predictions are correct. But given that there is no good reason to suspect that my diet can influence a coin toss the positive is more likely to be because of chance than because of a real effect. In this case then a higher standard of evidence would need to be achieved than if I had said I could alter the probabilities be sticking a piece of gum to one side.

All-in-all though this a very nice paper and my complaint is a small one, given the probable readership of the journal the inclusion of plausibility may even have alienated those that might otherwise have been receptive to the other points presented. I recommend reading it for yourself, it is a very easy and informative read.

Posted in Alternative medicine, Medicine, Questionable Techniques, Sciblogs, Science, skepticism Tagged: Alternative medicine, altmed, Expo, Hamilton, health, Health and Medicine, Medicine, Review, Science and Society

Evolution – The Story of Life Darcy Cowan Oct 03

2 Comments

I was sitting at my computer this morning wondering if I would suddenly be inspired with a topic to write about or whether I would resort to my default setting of abject sloth. Then inspiration did strike, in a way, my copy of “Evolution – The Story of Life” arrived by courier. Written by Douglas Palmer and illustrated by Peter Barrett this is a fantastic large format hardcover book that takes you on a trip through the history of life on planet Earth. From the appearance of single celled organisms, through the proliferation of forms during the Cambrian period and finishing up with the life we see around us today.

Evo

Beginning with introductory information explaining what evolution is as well as briefly covering the history of the theory, the time scales involved, taxonomy, fossils and how it all comes together this book will be accessible reading for anyone.

The book is beautifully illustrated throughout, touching upon each major stepping stone from the beginning to the present day. Every turn of the page brings a new vista with examples of flora and fauna typical of each age and location depicted. Below the impressive artwork is a brief description of the area and life shown as well as an information box showing a representation of the distribution of the continents at the time compared with how the particular location is situated today. Rounding out the informative package are photographs of actual fossils from the period.

Info Box

I was particularly taken with the Cladograms that show how the species of animals are related. The major levels of the tree of life each have their own cladograms; Metazoa, Tetrapoda, Mammalia and certainly not forgetting Primates.  These fantastic illustrations provide a great overview of the interrelatedness of species and are a fascinating read.

CladeFinally the book ends with a “Species listing”, an A-Z of the species depicted in the book featuring pictures of plants, animals and fossils. Each entry gives the time period the life form lived, it’s place within the tree of life, a brief description and the reference to were it can be found in the earlier pages of the book.

At the back of the book can be found a condensed timeline of the geological and evolutionary history of our planet. In addition all of the artwork in the book is reproduced side by side to show a continuous panoramic view of the story of life.

Evolution The Story of lifeI think I say without too much exaggeration that this book is truly a masterpiece and a great addition to any collection. Highly recommended.

Posted in Sciblogs, Science Tagged: Books, evolution, Review, Science and Society