|Jerry Don Bauer
Joined: Nov. 2012
|Quote (OgreMkV @ Dec. 04 2012,16:15)|
|Quote (Jerry Don Bauer @ Dec. 04 2012,15:55)|
|Quote (Henry J @ Dec. 04 2012,13:34)|
|Quote (Jerry Don Bauer @ Dec. 04 2012,10:16)|
|Are you really saying that there is not ONE individual that speciates when an entire population does?|
Yes, I am saying that.
Outside of some special cases like the one somebody else just mentioned, it goes something like this:
A species can accumulated changes over generations, these changes can add up.
Over a large number of generations, these changes can add up to enough to call it a different species, different than what it was many generations previously.
There is no point in which an individual is not in the same species as its recent ancestors.
It typically takes a lot of generations to accumulate enough change to justify calling it a new species.
If different subsets of a species evolve separately, i.e., without a significant amount of interbreeding, they can become different enough to call them separate species.
In the normal case there simply isn't a sharp boundary that might be jumped over in an instant. The observed boundaries between species are there because those species have been diverging for a long time, and have accumulated a lot of differences.
Where on earth did you GET this?
Let's start at the bottom....what does the word speciation mean:
"Speciation is the evolutionary process by which new biological species arise."
Stop right there as we need not complicate it any further at this point.
So, when does this new biological species arise? It arises when the definition of Earnt Mayr's (did I spell it right this time?) definition FOR a given sexual species is met:
organisms which can interbreed and produce viable, fertile offspring.
"Scientists have a pretty good handle on what constitutes a species for sexually reproducing animals: the biological-species concept. According to this concept, a species is a group of organisms that can interbreed and produce viable and fertile offspring."
AS LONG as the group we THINK are speciating can still interbreed with the population as a whole and meet the above definition with the old population, NOTHING has speciated........
And there is nothing mystical about it...the moment the new species can no longer viably interbreed with the old population, it becomes a new species.....NOT a minute before.
There you have it...it's not hard to wrap our heads around.
But there is a slight problem here....if our definition for a sexual species is correct.....it DOES NOT HAPPEN.....Experimentation shows that when a hybred IS produced that might meet the criteria, the offspring is ALWAY non-viable (it doesn't live) or it is infertile like mules and ligars.
So it would have been impossible for our little scenario to ever occur in the first place.
Second.....there MUST be individuals that number among this new, pretend population, or we don't have a population at all...How do you think it logically possible to have a population of organisms that are a new species, yet not to have ANY individuals comprising that population who have speciated? That's just nuts.
THIS KIND of illogical thinking is EXACTLY why you people are Darwinists.
No disrespect meant toward any one person, but considering you people as a group, as Voltaire once commented, "common sense is not so common.”
So to you Jerry, Lions and Tigers are the same species. Right?
Because they can mate. They can have offspring and those offspring are fertile.
You are wrong. Ligers are fertile.
|According to Wild Cats of the World (1975) by C. A. W. Guggisberg, ligers and tigons were long thought to be sterile: in 1943, a fifteen-year-old hybrid between a lion and an 'Island' tiger was successfully mated with a lion at the Munich Hellabrunn Zoo. The female cub, though of delicate health, was raised to adulthood.|
In September 2012, the Russian Novosibirsk Zoo announced the birth of a “liliger”, which is the offspring of a liger mother and a lion father. The cub was named Kiara.
10^ Guggisberg, C. A. W. "Wild Cats of the World." (1975).
11^ Katia Andreassi (21 September 2012). ""Liliger" Born in Russia No Boon for Big Cats". National Geographic.
|At the Alipore Zoo in India, a female tiglon named Rudrani, born in 1971, was successfully mated to an Asiatic Lion named Debabrata. The rare, second generation hybrid was called a litigon (/?la??ta???n/). Rudhrani produced seven litigons in her lifetime. Some of these reached impressive sizes—a litigon named Cubanacan (died 1991) weighed at least 363 kilograms (800 lb), stood 1.32 metres (4.3 ft) at the shoulder, and was 3.5 metres (11 ft) in total length.|
Reports also exist of the similar titigon (/?ta??ta???n/), resulting from the cross between a female tiglon and a male tiger. Titigons resemble golden tigers but with less contrast in their markings. A female tiglon born in 1978, named Noelle, shared an enclosure in the Shambala Preserve with a male Siberian Tiger called Anton, due to the keepers' belief that she was sterile. In 1983 Noelle produced a titigon named Nathaniel. As Nathaniel was three-quarters tiger, he had darker stripes than Noelle and vocalized more like a tiger, rather than with the mix of sounds used by his mother. Being only about quarter-lion, Nathaniel did not grow a mane. Nathaniel died of cancer at the age of eight or nine years. Noelle also developed cancer and died soon after.
So where's your species now?
I swear, the more I get to know you, the more I come to think that you are on here to INTENTIONALLY mislead and dupe the readers.
Ligars CANNOT have viable, fertile offpring with one another to propagate a species because MALE ligars do not have sperm.
But you already knew that, didn't you ... :O
"Male ligers do not produce viable sperm, but females can be fertile"
Of course, female ligars can be bred back, but certainly not in ANY MANNER that would propagate a new species with the male ligars.