So what are species anyway,
and how do new ones evolve? A species is often defined as a group of
individuals that actually or potentially interbreed in nature.
Example:
These spiders all look different but
since they can interbreed, they are considered the same species Theridion
grallator. (https://www.box.com/s/b8462f7d79b4f1dde03b)
The definition of a species is not really that simple
though. In nature there are a lot of places where it is difficult to apply
it. Many plants and animals
form hybrids in nature.
Example:
The hooded crows and carrion crows look
different, and largely mate within their own groups – but in some areas, they
hybridize. (https://www.box.com/s/6e66668145dc593a7675)
There are lots of other places where the boundary of a
species is blurred, but it is not so surprising that these blurry places exist
– after all, the idea of a species is something that we humans invented for our
own convenience. The existence of blurring between species will come in later
on…
Speciation is a lineage-splitting event that produces two or
more separate species
(Fruit Fly speciation-https://www.box.com/s/cdade614c83564592698)
Macroevolution:
I do not even feel that the word macroevolution needs to
exist because the only people that really use it are the ones that do not
understand what it means, thus forcing scientists explain it when the concepts
needed to understand it are actually complex.
So what is the difference between macro and microevolution?
Most people's initial answer is that microevolution is small
changes, and macroevolution is large changes. Though this simplistic explanation is
somewhat correct, it leads to a lot of confusion. Microevolution is
accepted even by creationists, and is the incremental small changes in the
genetic information passed on through generations of a species that can account
for differences in fur color, wing length, and body size, as well as bacteria
resistances to antibiotics. Changes
in the DNA passed on to the next generation can be selected for or against….
leading to things ranging from bacteria resistance to longer canines in a wild
cat. Though microevolution
has only been recently accepted by the creationists, this form of first stage
biological evolution is quite obvious as it can be seen in our lifetime in the
lab as well as in the wild.
Now, since we have already established that changes do develop in the DNA of every species that cause variation…what is the next step?
If there was a stage between a species being able to
interbreed and a species being split into two species that are no longer able
to interbreed…what do you think this would be? Before you read on, actually
try to think of a scenario that would be in between being able to interbreed
and have children and not being able to interbreed…
Using a math understanding…If you give the interbreeding
population the number 0, and the non-interbreeding populations a 1... The
amount that is between these is ½. So
in a simplistic sense, the stage between these two scenarios should be
literally half reproducing and half not reproducing. What this means is that on some level
they are able to interbreed but also are unable to. Okay, so what would that be? If you do not know the answer, it is
actually easier than you think.
You know the starting point is a single species, and the
endpoint is two different species that are no longer able to interbreed and
have been separated for millions of years… And you want to find that middle
stage, the ½ point…The example of the tiger and the lion, as well as the
awkward mating between the other big cats of the Panthera group, the leopard
and jaguar.
(Panthera Hybrid list-https://www.box.com/s/332fe414cbae63e18e11)
So for entertainment purposes… Let us look at a couple of these hybrids
Leopon: Proved to be sterile and the last
one died in 1985.
Tigard and Dogla: Tigards produced by
tiger/leopard matings are infertile, producing spontaneously aborted
"walnut sized fetuses", or in other words, "stillborn
offspring".
Liger and Tiglon: Can interbreed and produce fertile female hybrids and infertile male
hybrids
Jagger: There has been no report of the birth of
a healthy hybrid from a male jaguar and female tiger,
Why did I even do that?
Well! The big issue with the hybrids
is that they do not generally give rise to new species. Because hybrid males
are mostly infertile, hybridization is frequently a dead end because the
hybrids are not fully fertile. If the hybrids are fertile (almost always only
the females), they are usually absorbed back into the population of one or
other parent species and most of the alien genes are bred out. So if two cat groups which look
similar like the tiger and the lion though can though breed…cannot produce BOTH
male and female fertile offspring…This is then the first signs of speciation.
What could be considered more of a ½ stage then two similar
groups, who shared a common ancestor, being able to reproduce BUT their offspring
is incapable of continuing the line? This
is the case with practically all of the big cats in the Panthera group… And the
incompatibilities and fertility issues begin to grow larger when you move into
the next family that is most related to the big cats.
If you are someone who agrees with evolution… is not this exactly what you should have predicted?
Species that have not been separated
for long having issues reproducing… but then compared to the next closest
family they have even more? And
then compared to the next closest family, it grows larger? And will continue that way as you
compare them down the line? This
is exactly what happens, and this gradual progression of infertility growing
stronger and stronger as the groups become farther and farther apart, only
makes sense in the light of evolution.
If biological evolution was not true…
--Is it just a coincidence that very similar forms of
animals can interbreed though not produce fertile children? …
--As well as there being no example of something that looks
extremely different morphologically and genetically(cat to an antelope) that
can even remotely interbreed? …
--That every single time...when something can produce
infertile offspring…they always look like they came from the same
ancestor? …
--And if you move only a few million years away into a
different line that still resembles them (like the closely related civet), they
are now unable to produce any offspring? …
--And is it just coincidence that this next step is what you
would expect to see as a first reproductive issue, the offspring starting to
develop but ending up being stillborn? …
--And is it a coincidence that the more different groups
become, the genetic changes between them increases accordingly? …
I am sure you have noticed that all of the Panthera have
something in common… They all look like damn cats! And we are concerned about
macroevolution…so we want to see the cat give birth to a monkey or something
right? If this is what you
expect evolution to show, I am sorry I must disappoint you… because cats give
birth to cats… and monkeys give birth to monkeys…. So how did anything become
anything? What is our
evidence of it?
So in 2012 we have the four main Panthera species, the lion,
jaguar, tiger, and leopard....
Who is the last common ancestral group of the Panthera group?
We know from genetics as well as the fossil record that the
lion and the tiger have been separated, and have been accumulating differences
in their DNA for about 3.7 million years. A study based on mitochondrial genomes
of the Panthera told us that we should find the last common ancestor of the
Panthera at around 9-11 million years ago. These mitochondrial studies
then showed that the tiger and lion split away 6.55 million years ago, and the
leopard at 4.35 million years ago…and all of this genetic information
completely matches the fossil records, without a fossil out of place.
So the next closest living group to Panthera according to
morphological similarity and fossil record comparisons should still look quite
similar to the group though it should hold a couple traits separate from the
Panthera family… And this is where we find the snow leopard and the clouded
leopard. Both of these
belong in their own group separate from Panthera, as their family branched off
2-3 million years before the Panthera group developed and they have been
genetically diverging ever since. The clouded leopard diverged 8.66
million years ago and the snow leopard at 4.63 million years, and these two cats
are within their own more distant group but when combined with the Panthera
they are under the label “Pantherinae”.
The Pantherinae (lions, tigers, jaguars, and leopards + snow
leopards, cloudy leopards) are all still cats…though the snow leopard and
clouded leopard after being separated for longer, have even more issues
interbreeding with the more recent subgroup of Panthera (which is exactly what
you would expect).
Moving backwards we
should find a group that though is still a cat, should have further issues
interbreeding with the original starting point of the Panthera…and should have
even more, though slight, difference compared to the Pantherinae as a whole
morphologically as well as genetically. And
this brings us to the next closest family the Felinae, which consists of the
cheetah and the cougar, as well as the lynx ,
margay, serval, ocelot, bobcat, as well as many other endangered small
wildcats.
Now the Felinae group contains again…cats…but everyone in
this group, including my favorite animal in the world…the cheetah, CANNOT breed
with the original Panthera. Not one single bit. Yet…we consider them “cats”.
But now we see that within two major groups of cats, the Pantherinae and the
Felinae, though have only been separated for 10 million years, are no longer
able to breed with each other. Now this is where we will start to see some
major “macroevolutionary” differences
These are still considered “cats”…even though the two main subgroups can’t interbreed…So what is the next step?
Well now is where things get real
interesting…All of the next mammals are considered part of the Suborder
Feliformia, but are not Felidae, or not "cats". They are the next
steps that slowly start to change something cat-like into something civet-like
and then into a full blown civet. The civet is considered a different
"kind" from cats, and yet they have MANY issues placing these animals
into categories....Especially the first who just so happens to be the closest
living mammal to the cats that's not a "cat".
Asiatic Linsang - (https://www.box.com/s/ina4bhjarn44yluazfx0)
Genet - (https://www.box.com/s/1ou7b7eyd0qb39o2toa8)
Asian Palm Civet - (https://www.box.com/s/uafni43txfsm0o2pbx8u)
African Palm Civet (https://www.box.com/s/8nvutnuoh9ugdms248av) & (https://www.box.com/s/hztb9gvkd3m6ox60zwkd)
No matter what group you give me, if you want to know the
blurring lines I will show you and let you decide for yourself. Cats, dogs, reptiles, fish, humans,
amphibians, birds, insects… You will always follow the line backwards until you
find that blurring point genetically, morphologically, and
reproductively. And these
blurring points only makes sense in the light of biological evolution.
So we have hit the awkward blurring point between the group
of “cats”, the Felinae, like the cheetah and Lynx, and the next closest group
containing the civet.
The civet belongs to the group Viverridae, which you do not
have to remember that name, but if you want to see the members of this
important blurring group, you should check into them. Some of them look more cat-like than
others, and some of them are starting to look like large tree squirrels…
(Viverridae family photo-https://www.box.com/s/28e6971d238b6beb0ae1).
Use your own judgment on what you think is considered more
cat-like, just be sure to compare that to the least cat-like of the group
Viverridae and then compare it to the slightly more cat-like Felinae. I guarantee you will not be able to
make distinctions between them, and yet they are all linked up to the Panthera
“big cats” we know today.
If you are following along so far, be proud of yourself
because it is a lot of information and a lot of scientific names… But every
single one of these can be googled or possibly be found at your local
zoo. You do not need me to
tell you what is more cat-like, and that is the beauty of evolution… The
ability to see things on your own. We
now hit I believe the most interesting part of this whole feline evolution rant
that is lasted way too long…
Hyena's are part of the cat-like family.
They are Feliformia
not Caniformia. And to keep things short, in the fossil record, hyenas look
just like civets and slowly develop into hyenas...
(Civet-like ancestor comparison-https://www.box.com/s/94a45af43e958e4a4af6)
Canids (dogs, wolves, foxes) or the dog-like carnivores do
not come from the cat-like civet family Viverridae so hyena's having a
civet-like fossil record show it developed from the same cat-like ancestors as
the big cats today and this is matched genetically...more on this another time!
This evidence takes no faith at all.
If the differences between the civet,
the hyena, and the lion are not examples of observable evidence for the incremental
microevolutionary changes that lead to the broad term of macroevolution… Then I
do not know what is.
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