One I read about years ago about lizards on islands off Croatia. Lizards Rapidly Evolve After Introduction to Island Whether this is enough to satisfy the “microevolution versus macroevolution” argument, I don’t know, but I suspect nothing is.
I think that “microevolution” is defined as “the kind of evolution that happens”, and “macroevolution” is defined as “the kind that doesn’t”.
This is also invoked in defense of Noah’s Ark: Noah didn’t take one of every species, he took one of every “kind”, the same “kinds” within which microevolution is possible.
It’d have to be around 60 Ma - 20 Ma, that’s the window for this. And “chunk of driftwood” is a bit of an understatement, more like a giant raft of storm-driven vegetation probably including multiple downed trees and bushes, all matted together.
Well quite, in just the past couple of decades we have seen two major tsunami events. Each of which is capable of dislodging terrestrial species and forming floating mats that can support terrestrial life for long enough to reach other islands. Once you have isolated populations all you have to do is add time, genetic mutation and selection pressures. Speciation is pretty much then a given.
And those are just the two most obvious and remarkable events in that (geologically and biologically negligible) time-frame. You mention storms and in that period there have been countless other storm-surges and meteorological events that can do much the same.
None of the above is even remotely in contest and it is a constant source of wonder to me that some outwardly educated people are able to ignore it.
Indeed they do, then they conveniently ignore the questions about the lack of recent transitional remains, or residual populations along the assumed migration routes of, say, kangaroos or Alpaca.
Sure, to anybody who actually wants to know the answer.
With people who are already convinced they know the (wrong) answer, it’s highly unlikely to work.
While this is mostly true of [allopatric speciation](Allopatric speciation - Wikipedia, it’s not true of other mechanisms of speciation.
When sexual reproduction occurs, on rare occasions the sperm or egg might contain a full set of chromosomes rather than the typical half-set. When the sperm and egg fuse, the offspring will have a different number of chromosomes from the parents, and will be unable to interbreed with the original population.* The new offspring are then a new species, and can produce new individuals using asexual reproduction, who can then interbreed with each other.* This mechanism of speciation is called polyploidy and is surprisingly rapid. There are examples, mostly in the plant world, including a Scottish Monkeyflower, but there are a few animal examples too.
Some types of speciation are pretty rapid and would cause Creationists to change their minds if they were the sort of people who were interested in evidence in the first place.
*Usually; like with anything in biology, there are exceptions
Caution: any taxonomy by its sheer definition is drawing a line in a fairly arbitrary place.
If you use the inter-breeding criteria of defining a species is problematic even for Homo sapiens
Consider finding Bison bison breeding stock that doesn’t have a large amount of Cattle DNA as another example.
Maize, bananas, goldfish, drug resistant MRSA ,and domestic sheep are great examples of punctuated evolution if you care about the “selection” part.
Aren’t bacteria pretty constantly evolving? Aren’t antibiotic resistant strains pretty widely publicized and accepted proof of that? (Although I’m not exactly sure what the OP intends by his use of the term “species.”)
[quote=“thorny_locust, post:16, topic:838763”]
Ah, you haven’t run into the microevolution versus macroevolution theories yet.
[quote]
I have …just not in the hard bright line way that creationists seem to be using it.
My experience with the concept is more of them being interrelated. Microevolution can over time build up to produce something that we’d label a new species. ISTM that even ring species examples would run into serious issues of being handwaved away as microevolutionary changes for those that draw that hard line.
Epigenetics would seem to have the potential to allow substantial ‘evolution’ within species. It is a nascent field and has the potential to change the way we think evolution works. (Plus, Lamarckism, is too good not to be true ;))
There’s a lot of evidence that C.Diff. is evolving. One paper suggests that one group is on the verge of becoming a new species.
It’s a bug you might get in the hospital or when you’ve finished taking anti-biotics.
While I think these are all interesting examples of evolution in action and I’ve learned a lot, I’m not sure they are explicit enough to convince any skeptic. They are all probably too minor and subtle. I think the evolution doubters would need something undeniable like a school of trout in the wild turning into a completely new kind of land mammal within a few generations, and that they could see the transformation themselves.
I’m wondering how long it will take road kill species to figure out how to avoid those loud shiny things with lights.
The canada geese around here seem to have figured out how to cross roads. Obnoxious, but it works.
If they bothered to learn how evolution works, what mechanisms come into play, they would know that trout becoming mammalian won’t happen in a few generations. Evolution isn’t a magic wand.
Modern humans with European ancestors have some genetic material from Neanderthals, humans from Central Asia have some Denisovan DNA.
They clearly bred with Homo Sapians and produced offspring that could also reproduce so why are they considered different species?
I think part of the confusion is the many ways in which the word “species” is used. We say something like “many species of wolves”. But seeing how most kinds of wolves can mate with each other, they would be considered the same species according to this definition from wikipedia:
Other definitions add that the members of a species also share common attributes. If it’s defined that way, then each sub-type would be considered their own species. So with dogs, each breed could be considered a unique species (lab, bullnose, pug, etc). The same with all the humanoid ancestors in the past since each kind had their own set of common attributes.
That all adds to the confusion when trying to explain new species emerging from evolution. It’s not always clear what is meant by species.
The most-often-used definition of species is that the individuals can and routinely do, in nature mate to produce viable, fertile offspring. By this standard, domesticated animals are always considered part of the same species as their wild ancestors (Canis lupus, for dogs), because there is no “natural” population of domesticated animals.
Personally, I’m not fond of this definition, because it can result in apparent speciation just through natural barriers. For instance, Pan trogolodytes and Pan bonobo (the two populations of chimps) are separated by the Congo River, which neither is able to swim across. If they came in contact, would they mate? Quite likely. But they don’t, because they don’t ever come in contact.
Or, even closer to home, for thousands of years the human populations of the Americas and the Old World didn’t routinely mate, because of the oceans in the way. Were they separate species for that time? And yet, as soon as they were re-introduced to each other, they enthusiastically mixed.
I don’t know if this is fact or not but many years ago I read somewhere that a raccoon dog has a variable chromosome count and could theoretically breed outside of it’s species and create a new species. The writer suggested this could explain how animals like bears, canines, cats and weasel family may have gotten started. I honestly don’t buy it but maybe someone here has more info on that. Chronos??
If they lack the abilty to understand evolution to the extent that that is what they expect, then there is pretty much no evidence that’ll convince them.
Their standpoint is the same as not accepting mountain ranges arise from plate tectonics because we’ve never seen flat sea-bed become mountain-top in our lifetme.