What should everyone know about paleontology?
Dinosaur expert Tom Holtz summarizes the key points of paleontology for the general audience:
[…] The title question was recently asked by Roberto Takata on the Dinosaur Mailing List ( dml.cmnh.org ).
I think that is a good question. What really are the most important elements of paleontology that the general public should understand?
I took a shot at coming up with a list of key concepts […] based on experiences with teaching paleontology and historical geology and with less-formally structured outreach to the public. I have offered this list […] as a way for it to reach a wider audience. That this is Darwin Week makes it even more appropriate, as we should use this occasion to encourage a better understanding of the changes of Earth and Life through Time for the public at large.
[A]ll human societies and many individuals have wondered about where we have come from and how the world came to be the way it is. This is, in my opinion, the greatest contribution of paleontology: it gives us the Story of Earth and Life, and especially our own story.
Tom then goes on to make a list of general topics that he thinks everyone ought to know, including:
[… F]ossils are necessarily incomplete, and there will always be information about past life which we might very much want to know, but which has been forever lost. Accepting this is very important when working with paleontology.
That environments of the past were different from the present.
That there have been episodes of time when major fractions of the living world were extinguished in a very short period of time: such data could not be known without the fossil record.
That entire branches of the tree of life have perished (sometimes in these mass extinction events, sometimes more gradually).
These are important ideas because we have to accept that we will never have complete information from the past.
Tom then goes on to list some specifics related to humans, but first starts with a lament:
Honestly, despite the fact the specific issues about specific parts of the Tree of Life are the ones that paleontologists, the news media, the average citizen, etc., are more concerned with, they really are much less significant for the general public to know than the points above. Sadly, documentary companies and the like keep on forgetting that, and keep on forgetting that a lot of the public does not know the above points.
Really, in the big picture, the distinction between dinosaurs, pterosaurs, and crurotarsans are trivialities compared to a basic understanding that the fossil record is our document of Life’s history and Earth’s changes.
Summarizing the key points of the history of life over nearly 4 billion years of evolutionary history is a big task. After all, there is a tendency to focus on the spectacular and sensationalized rather than the ordinary and humdrum. As Stephen Jay Gould and others often remarked, from a purely objective external standpoint we have always lived in the Age of Bacteria, and the changing panoply of animals and plants during the last half-billion years have only been superficial changes.
Yes, the tendency is to focus on the controversial and sensational, which means that the public often gets the idea that whole fields of science are themselves up for doubt.
Anyway, Tom’s list of specific concepts from paleontology that leads up to us:
Life first developed in the seas, and for nearly all of its history was confined there.
For most of Life’s history, organisms were single-celled only. (And today, most of the diversity remains single-celled).
[… many steps]
A group of arboreal mammals with very big brains, complex social communities, and gripping hands—the primates—produced many forms. In Africa one branch of these evolved to live at mixed forest-grassland margins, and from this branch evolved some who became fully upright and moved out into the grasslands.
This group of primates retained and advanced the ability to use stone tools that its forest-dwelling ancestors already had. Many branches evolved, and some developed even larger brains and more complex tools. It is from among these that the ancestors of modern humans and other close relatives evolved, and eventually spread out from Africa to other regions of the planet.
About 2.6 million years ago a number of factors led to ice age conditions, where glaciers advanced and retreated. Various groups of animals evolved adaptations for these new cold climates.
The early humans managed to colonize much of the planet; shortly after their arrival into new worlds, nearly all the large-bodied native species disappeared.
At some point before the common ancestor of all modern humans spread across the planet, the ability to have very complex symbolic language evolved. This led to many, many technological and cultural diversifications which changed much faster than the biology of the humans themselves.
In western Asia and northern Africa (and eventually in other regions), modern humans developed techniques to grow food under controlled circumstances, leading to true agriculture. (Other cultures are known to have independently evolved proto-agricultural techniques).
This Neolithic revolution allowed for the development of more settled communities, specialization of individual skills within a community (including soldiers, metallurgists, potters, priests, rulers, and with the rise of writing, scribes).
From this point we begin to get a written record, and so the historians can take up the story…
Worthwhile reading the entire lists at the link.
Yes, roughly 40% of our society is composed of Young Earth Creationists and reject the entire field of paleontology. Even those in our society who nominally give assent to an old Earth and the idea of evolution are not familiar with the actual body of knowledge that has been gathered - so this compilation of concepts that summarize the findings of paleontology are a good place to start to get the big picture.