From the site True.Origin:

"As one of his supporting pieces of “evidence,” Quammen leaned heavily on biogeography—a branch of science that attempts to document and understand spatial patterns of biodiversity among plants and animals. In speaking of Darwin, Mr. Quammen commented:

Biogeography, for instance, offered a great pageant of peculiar facts and patterns. Anyone who considers the biogeographical data, Darwin wrote, must be struck by the mysterious clustering pattern among what he called “closely allied” species—that is, similar creatures sharing roughly the same body plan. Such closely allied species tend to be found on the same continent (several species of Zebra in Africa) or within the same group of oceanic islands (dozens of species of honeycreepers in Hawaii, thirteen species of Gal�pagos finch), despite their species-by-species preferences for different habitats, food sources, or conditions of climate�. Why should “closely allied” species inhabit neighboring patches of habitat? And why should similar habitat on different continents be occupied by species that aren’t so closely allied? “We see in these facts some deep organic bond,” Darwin wrote. “This bond, on my theory, is simply inheritance.” Similar species occur nearby in space because they have descended from common ancestors (pp. 9-10, parenthetical items in orig, emp. added).
So there you have it. Because certain plants or animals share “roughly the same body plan” and “tend to be found on the same continent,” they therefore are genetically related, and have come from a common ancestor. Evolutionists suggest that only evolution can explain why there are certain creatures in one location (like kangaroos in Australia), but not in another location.

One thing Mr. Quammen apparently “forgot” to mention as he was discussing his “evidence” is that biogeography is usually not even an “experimental” science. It is mostly a comparative observational branch, due to the fact that the spatial and temporal scales are commonly too large for true experimentation. Thus, this field speculates about what determines where a species to lives, and what prevents it from colonizing in other areas. Most biogeographers try to evaluate three processes in explaining what is found in nature: evolution; extinction; and dispersal. Obviously, however, formulating theories and predictions while having already accepted evolution as a “fact,” will grossly bias any interpretation of the scientific data.

For instance, we know today that many species have suspicious resemblances to supposedly different species that “just happen” to live nearby. They appear this way, even though another species—designed differently—would seem to be a better fit. For example, the trees on the remote island of St. Helena are unlike the trees anywhere else on Earth. Sunflowers appear to be the “closest relative” to the strange gumwood tree and to the native cabbage-trees. And, the most closely related sunflower is the local sunflower. The scientific explanation is that this volcanic island originally was formed far away from any continent, and therefore started out with no land plants. Eventually, some sunflower seeds managed to get there. Since nothing else was filling the role of “tree,” these sunflowers filled that role. Transformed by time, competition, and the demands of their role, they now look like trees. The only problem with this explanation is that no macroevolution has occurred. Sunflowers are still sunflowers.

Examples like this can be found on almost every remote island, and evolutionists are quick to try and use such examples as proof for their theory. In the Gal�pagos Islands, the absence of woodpeckers has caused some finches—which obtain their food in a manner similar to woodpeckers—to fit into the “woodpecker” niche. Most scientists today suspect that finches were one of the only “land birds” to occupy the Gal�pagos, and as such, the birds have modified beaks that allow them to take advantage of various food sources. Moving to the North American continent, we now know that birds are the same on both sides of the Grand Canyon, yet there are different rodents on each side. The obvious explanation is that the canyon isolates groups of rodents, but does not isolate birds. Such differences permit us to speculate on what allows a species to live where it does, but they do not tell us anything about how the species got there in the first place!

Explaining such things as the origin of Australia’s marsupial population is just as difficult for evolutionists as they claim it is for creationists. Marsupials like kangaroos, opossums, wallabies, and koalas seem unusual, but monotremes (i.e., the echidna and the platypus) are even more puzzling. The main difference between marsupials and most other mammals centers on the reproductive system. Marsupials give birth prematurely, and allow the fetus to develop in an external pouch. In other mammals, (excluding the monotremes, which lay eggs), the fetus develops within the uterus and is attached to, and nourished by, the placenta. Neither biogeography nor evolution can explain why animals sharing the same tree, reproduce using an internal uterus (e.g., squirrels) as opposed to an external pouch (e.g., opossums).

One of the most interesting facts about marsupials is that they nearly all have non-marsupial equivalents in other parts of the world (see Dobzhansky, et al., 1977, Figure 9.3, p. 267). The kangaroo has a similar role to the antelope that roams the African savanna. The wombat resembles a badger, and even has a backward-pointing pouch so that it will not fill with dirt while burrowing! There also are many small marsupials that have rodent counterparts. Evolutionists, of course, are forced to attribute such similarities to “parallel evolution” in both homology (being alike in form) and analogy (occupying a corresponding niche). That is, they believe that these marsupials and their placental peers developed independently—while they share similar characteristics, they took different paths to get there (see Simpson and Beck, 1965, pp. 499-501). A common ancestry, combined with similar forces of natural selection, evolutionists assert, will result in the same sort of changes through time. This common ancestor is thought to be the opossum because it is a marsupial, and is found in other areas of the world apart from Australia.

According to evolutionary theory, the opossum was a primitive mammal living 200 million years ago on a single southern land mass called Gondwanaland. When parts of this supercontinent divided into what are now Australia and South America, the opossums were separated geographically. Over eons of time, so the story goes, the Australian descendants of the opossum developed into the various types of marsupials seen today. But in South America, they “evolved” placentas and eventually migrated to North America and Eurasia. These evolutionary theories, however, suffer from a number of problems.

(1) There are no intermediate fossils (“transitional forms”) showing the development of the marsupials from an opossum or opossum-like ancestor. Furthermore, to suggest that one type of mammal could arise by supposed evolutionary mechanisms is incredible enough, but the probability of having both placental and non-placental forms evolve in the same way, at the same time, and in different regions, is remote, to say the least.

(2) The humble opossum has been nominated as the ancestor of all mammals because it is supposed to be so “primitive,” having a relatively small brain and no “specialized” characteristics. But the opossum has thrived virtually unchanged in many parts of the world. In general, marsupials are often considered less “advanced” because they lack the complex internal reproductive system of placental mammals. However, they possess many other characteristics that could give them an edge over their placental counterparts. For instance, a female kangaroo can nourish two young ones of different ages at the same time, providing the appropriate formula from each teat. Unlike placental mammals, marsupials can suspend or abort the embryo deliberately if adverse conditions arise. And, of course, the pouch provides a superior place of protection for the young marsupial. Yes, marsupials are different, but they are not inferior.

(3) The distribution of marsupials is not well answered by evolutionary theories. According to Michael Pitman, “the most diverse fossil assemblies have been obtained from South America and, later (Pliocene), Australia” (1984, p. 206, parenthetical item in orig.). That is, according to the fossil record, the marsupials already were well defined as a distinct group before the alleged separation of Australia from other continents. Thus, geographic separation cannot be as significant to their development as evolutionists like to think (or as they would like everyone else to think).

There also are numerous other puzzles in regard to the distribution of living (and/or fossil) organisms. For example, evolutionists are forced to admit that marsupials once lived in Europe, Asia, and in abundance in North America, yet now are largely absent (except for opossums in the Americas). Consider the following revealing admission from two evolutionists:

Living marsupials are restricted to Australia and South America (which were part of the supercontinent Gondwana); North American opossums are recent immigrants to the continent. In contrast, metatherian fossils from the Late Cretaceous are exclusively from Eurasia and North America (which formed the supercontinent Laurasia). This geographical switch remains unexplained (Cifelli and Davis, 2003, 301:1899-1902, emp. added).
Closely related species in a certain geographical area (like the thirteen species of finches in the Gal�pagos Islands that Quammen mentioned—species which, by the way, are now known to be interbreeding!)—may well have arisen from a single, original species (a.k.a., a “common ancestor”). But that says nothing about where that single original species came from. “A finch ‘changing’ into a finch” does not offer any explanation whatsoever as to how finches originated in the first place. Such instances are textbook examples of sorting already-present genetic information (and far more rapidly than evolutionists would expect!). But they are not examples of generating new information. Furthermore, studies have now shown that many changes are actually the result of a built-in capacity to respond (i.e., adapt) to cyclically changing climates. For example, while a drought might result in a slight alteration in the specific size of a finch’s beak, whatever changes take place during such a period of stress rarely are permanent. The finch’s beak generally returns to the original condition once the drought ends. This same type of argumentation applies to the other examples (anoles, mole rats, ants, pigeons, and fruit flies) that Quammen employed in his National Geographic article.

Ascribing evolutionary interpretations to events we find in nature does not make those events the product of organic evolution. Regardless of what David Quammen thinks, and contrary to what his November 2004 National Geographic article implies, creationists have no problem whatsoever with the production of new species—which are the end result of the reshuffling (or loss) of the genetic information in the original created kinds of organisms. The disagreement in science today between evolutionists and creationists is not about the production of new species. Rather, it is about the production of those groupings beyond the species level (genus, family, class, order, or phylum). Instances from biogeography of “closely allied” species says nothing whatsoever about how one kind of organism was able to “evolve” into another kind of organism.

When Darwin said that he saw in the facts of biogeography “some deep organic bond,” he was seeing exactly what he wanted to see, not what the data themselves revealed. And when David Quammen, 145 years later, said that “similar species occur nearby in space because they have descended from common ancestors,” he was doing exactly the same. The facts are one thing; the interpretation of the facts is something else entirely."