Log in
Register
Search
Search titles only
By:
Search titles only
By:
Forums
New posts
Forum list
Search forums
Leaderboards
Games
Our Blog
Blogs
New entries
New comments
Blog list
Search blogs
Credits
Transactions
Shop
Blessings: ✟0.00
Tickets
Open new ticket
Watched
Donate
Log in
Register
Search
Search titles only
By:
Search titles only
By:
More options
Toggle width
Share this page
Share this page
Share
Reddit
Pinterest
Tumblr
WhatsApp
Email
Share
Link
Menu
Install the app
Install
Forums
Discussion and Debate
Discussion and Debate
Physical & Life Sciences
Creation & Evolution
Statements About Evolution
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Kylie" data-source="post: 76864828" data-attributes="member: 343110"><p>What I mean is that the average number of offspring produced by individuals with this trait will be slightly above the average for the whole population.</p><p></p><p>For example, a zebra can produce an offspring every two or three years. The exact time will depend on many factors, but an important one will be the zebra's ability to prepare its body. After all, producing offspring is a rather intensive process and takes a lot of energy and resources.</p><p></p><p>If a zebra has genes that mean she is better able to store energy reserves, for example, she may find that her body is better able to prepare for producing an offspring. As such, she might be able to reproduce every two years. A different zebra without this gene will be closer to the average, say, 2.5 years. Since Zebras have a breeding season, this would work out to a gap of two years, then a gap of three years, and alternating in this way (remember, this is on average). But a zebra that has genes that leave her poorly prepared may find that it takes her three years every single time.</p><p></p><p>So, let's follow the herd of zebra over the course of a decade, say 2000 to 2010. The first zebra (with the genes which help her reproduce) is able to fall pregnant 6 times, in 2000, then in 2002, 2004, 2006, 2008 and 2010. The average zebra will fall pregnant 5 times, in 2000, 2002, 2005, 2007 and 2010. And the below average zebra will fall pregnant 4 times, in 2000, 2003, 2006 and 2009. If we assume all other things are equal (the chances of any foal succumbing to disease or predators, for example), then the zebras with the genes for the improved ability to store reserves have produced more offspring in the same time, and the zebras with the worse ability have produced fewer offspring.</p><p></p><p></p><p></p><p>This fits in perfectly well with evolution, actually. Yes, mules have many benefits over horses and donkeys. But the fact that they can't produce offspring of their own prevents the "mule" combination of genes from spreading. Let's say that there was a herd composed of horses and donkeys. And let's also say that (for the purposes of this example) mules <em>could</em> produce offspring. Surely, you would expect to find that mules start off as quite rare (after all, the herd is mostly horses and donkeys at the start). But while there will be cases of horses breeding with horses and donkeys breeding with donkeys, there will also be cases where horses and donkeys interbreed.</p><p></p><p>If we assume that the chances of a male of one species breeding with a female of the other species, there are four different pairings available:</p><p></p><p>Male horse breeds with female horse</p><p>Male horse breeds with female donkey</p><p>Male donkey breeds with female horse</p><p>Male donkey breeds with female donkey</p><p></p><p>If each of those pairings is random, then fully half the pairings will be between a horse and a donkey, producing mules. And if mules are on average better than either horses or donkeys (specifically referring to how well they are able to produce offspring of their own, whether it be by being better able to survive in general, or by being better able to gain access to a mate), then we would expect to see that over multiple generations, the mules quickly increase within the population until they dominate it. If we came back to check the heard after many generations, we'd find most members of this herd would be mules.</p><p></p><p>But as you said, mules are sterile and can't produce any offspring of their own. So in our hypothetical herd, fully half the pairings would lead to an evolutionary dead end. Evolution is changes accumulating over generations, and getting those generations requires reproduction. Since the mules can't breed, they can't pass on any genes, and so their line ends with them.</p><p></p><p></p><p></p><p>Do you mean cases of two individuals from different species interbreeding? As you pointed out in your mule example, that is impossible for all practical purposes. If you are talking about a population of one species evolving into a population of a different species, that's what I'm leading to. But I'm just laying the framework at the moment, since I'd like you to have an understanding of the <em>process</em> rather than just making the claim and saying you have to accept it without understanding it.</p></blockquote><p></p>
[QUOTE="Kylie, post: 76864828, member: 343110"] What I mean is that the average number of offspring produced by individuals with this trait will be slightly above the average for the whole population. For example, a zebra can produce an offspring every two or three years. The exact time will depend on many factors, but an important one will be the zebra's ability to prepare its body. After all, producing offspring is a rather intensive process and takes a lot of energy and resources. If a zebra has genes that mean she is better able to store energy reserves, for example, she may find that her body is better able to prepare for producing an offspring. As such, she might be able to reproduce every two years. A different zebra without this gene will be closer to the average, say, 2.5 years. Since Zebras have a breeding season, this would work out to a gap of two years, then a gap of three years, and alternating in this way (remember, this is on average). But a zebra that has genes that leave her poorly prepared may find that it takes her three years every single time. So, let's follow the herd of zebra over the course of a decade, say 2000 to 2010. The first zebra (with the genes which help her reproduce) is able to fall pregnant 6 times, in 2000, then in 2002, 2004, 2006, 2008 and 2010. The average zebra will fall pregnant 5 times, in 2000, 2002, 2005, 2007 and 2010. And the below average zebra will fall pregnant 4 times, in 2000, 2003, 2006 and 2009. If we assume all other things are equal (the chances of any foal succumbing to disease or predators, for example), then the zebras with the genes for the improved ability to store reserves have produced more offspring in the same time, and the zebras with the worse ability have produced fewer offspring. This fits in perfectly well with evolution, actually. Yes, mules have many benefits over horses and donkeys. But the fact that they can't produce offspring of their own prevents the "mule" combination of genes from spreading. Let's say that there was a herd composed of horses and donkeys. And let's also say that (for the purposes of this example) mules [I]could[/I] produce offspring. Surely, you would expect to find that mules start off as quite rare (after all, the herd is mostly horses and donkeys at the start). But while there will be cases of horses breeding with horses and donkeys breeding with donkeys, there will also be cases where horses and donkeys interbreed. If we assume that the chances of a male of one species breeding with a female of the other species, there are four different pairings available: Male horse breeds with female horse Male horse breeds with female donkey Male donkey breeds with female horse Male donkey breeds with female donkey If each of those pairings is random, then fully half the pairings will be between a horse and a donkey, producing mules. And if mules are on average better than either horses or donkeys (specifically referring to how well they are able to produce offspring of their own, whether it be by being better able to survive in general, or by being better able to gain access to a mate), then we would expect to see that over multiple generations, the mules quickly increase within the population until they dominate it. If we came back to check the heard after many generations, we'd find most members of this herd would be mules. But as you said, mules are sterile and can't produce any offspring of their own. So in our hypothetical herd, fully half the pairings would lead to an evolutionary dead end. Evolution is changes accumulating over generations, and getting those generations requires reproduction. Since the mules can't breed, they can't pass on any genes, and so their line ends with them. Do you mean cases of two individuals from different species interbreeding? As you pointed out in your mule example, that is impossible for all practical purposes. If you are talking about a population of one species evolving into a population of a different species, that's what I'm leading to. But I'm just laying the framework at the moment, since I'd like you to have an understanding of the [I]process[/I] rather than just making the claim and saying you have to accept it without understanding it. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Discussion and Debate
Discussion and Debate
Physical & Life Sciences
Creation & Evolution
Statements About Evolution
Top
Bottom