41–60 of 69
Recently, President Bush declared the vast ocean and archipelago known as the Northwestern Hawaiian Islands as a national monument. At 1,400 miles long and 100 miles wide, the site is loo times larger than Yosemite National Park, larger than forty-six of the fifty states, and home to more than 7,000 marine species…
Nature progresses by unknown gradations and consequently does not submit to our absolute division when passing by imperceptible nuances, from one species to another and often from one genus to another. Inevitably there are a great number of equivocal species and in-between specimens that one does not know where to…
As for me ... I would much rather be a perfected ape than a degraded Adam. Yes, if it is shown to me that my humble ancestors were quadrupedal animals, arboreal herbivores, brothers or cousins of those who were also the ancestors of monkeys and apes, far from blushing in shame for my species because of its genealogy…
Every save-the-world cause has a list of suggestions for “what each of us can do”: bike to work, recycle, and so on. I can propose such a list related to the problems I’m talking about: Don’t post anonymously unless you really might be in danger. If you put effort into Wikipedia articles, put even more effort into…
The file is a set of philosophical ideas made into eternal flesh. The ideas expressed by the file include the notion that human expression comes in severable chunks that can be organized as leaves on an abstract tree—and that the chunks have versions and need to be matched to compatible applications.
Evolution is neither moral nor immoral. It just is, and we make of it what we will. I have tried to show that two things we can make of it are that it’s simple and it’s marvelous. And far from constricting our actions, the study of evolution can liberate our minds. Human beings may be only one small twig on the vast…
In response to these distasteful episodes of racism, some scientists have overreacted, arguing that human races have no biological reality and are merely sociopolitical “constructs” that don’t merit scientific study. But to biologists, race—so long as it doesn’t apply to humans!— has always been a perfectly…
The way we discovered how species arise resembles the way astronomers discovered how stars “evolve” over time. Both processes occur too slowly for us to see them happening over our lifetime. But we can still understand how they work by finding snapshots of the process at different evolutionary stages and putting these…
What keeps members of two related species from mating with each other? There are many different reproductive barriers. Species might not interbreed simply because their mating or flowering seasons don’t overlap. Some corals, for example, reproduce only one night a year, spewing out masses of eggs and sperm into the…
And when we think of why we feel that brown-eyed and blue-eyed humans, or Inuit and !Kung, are members of the same species, we realize that it’s because they can mate with each other and produce offspring that contain combinations of their genes. In other words, they belong to the same gene pool. When you ponder…
Mayr lived exactly 100 years, producing a stream of books and papers up to the day of his death. Among these was his 1963 classic, Animal Species and Evolution, the very book that made me want to study evolution. In it Mayr recounted a striking fact. When he totaled up the names that the natives of New Guinea’s Arfak…
We can even see the origin of new, ecologically diverse bacterial species, all within a single laboratory flask. Paul Rainey and his colleagues at Oxford University placed a strain of the bacteria Pseudomonas fluorescens in a small vessel containing nutrient broth, and simply watched it. (It’s surprising but true that…
The most famous example of different species filling similar roles involves the marsupial mammals, now found mainly in Australia (the Virginia opossum is a familiar exception), and placental mammals, which predominate elsewhere in the world. The two groups show important anatomical differences, most notably in their…
A good example of bad design is the flounder, whose popularity as an eating fish (Dover sole, for instance) comes partly from its flatness, which makes it easy to bone. There are actually about 500 species of flatfish— halibut, turbot, flounders, and their kin—all placed in the order Pleuronectiformes. The word means…
Because reptiles appear in the fossil record before birds, we can guess that the common ancestor of birds and reptiles was an ancient reptile, and would have looked like one. We now know that this common ancestor was a dinosaur. Its overall appearance would give few clues that it was indeed a “missing link”—that one…
I have found it difficult, when looking at any two species, to avoid picturing to myself, forms directly intermediate between them. But this is a wholly false view; we should always look for forms intermediate between each species and a common but unknown progenitor; and the progenitor will generally have differed in…
It may very properly be asked whether the attempt to define distinct species, of a more or less permanent nature, such as we are accustomed to deal with amongst the higher plants and animals, is not altogether illusory amongst such lowly organised forms of life as the bacteria. No biologist nowadays believes in the…
Not all babies are the same. Human babies are rather helpless, interested mostly in food, sleeping, eating, defecating, and comfort. Compare human babies with newborn deer. When fawns are born, they immediately stand up and soon are able to run away from danger. Scientists call these two types of babies in the animal…
Most human and natural communities now consist both of long-term residents and of new arrivals, and ecosystems are emerging that never existed before. It is impractical to try to restore ecosystems to some ‘rightful' historical state. For example, of the 30 planned plant eradication efforts undertaken in the Galapagos…
In 1917 the great Scottish zoologist D'Arcy Thompson wrote a book called On Growth and Form, in the last chapter of which he introduced his famous 'method of transformations'. * He would draw an animal on graph paper, and then he would distort the graph paper in a mathematically specifiable way and show that the form…