Term
| Morphological species concept |
|
Definition
| Distinguishing among different types of organisms in terms of their phenotypes. |
|
|
Term
| Biological species concept |
|
Definition
| this defines species as groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups |
|
|
Term
|
Definition
| , a species is comprised of populations whose members mate and produce offspring or they would if they were able to come in contact with one another. And at the same time the BSC indicates that different species do not mate or cannot produce fertile offspring |
|
|
Term
|
Definition
| before zygote,mechanisms these over here prevent sex or prevent the fertilization of eggs from occurring temporal, behavioral, mechanical, and gametic |
|
|
Term
|
Definition
| that occur after the zygote, mechanisms prevent the proper functioning of those zygotes. |
|
|
Term
|
Definition
| populations that are physically or geographically separated, are by definition reproductively isolated from one another |
|
|
Term
|
Definition
| Populations that are not physically separated |
|
|
Term
|
Definition
| Populations that are not physically separated,species that utilize different parts of the environment may rarely come into contact with one another and this itself may prevent breeding and this is the idea of closely related concept to geographical isolation of ecological isolation. |
|
|
Term
|
Definition
| So individuals in allopatric populations often are by definition reproductively isolated from one another. |
|
|
Term
|
Definition
| isolations occurs when species reproduce in different seasons or at different time of day. These are two species of wild lettuce,They occur sympatrically. They can easily produce fertile hybrids in the lab, but they never do so in nature. Why? Because Lactuca graminifolia, this one flowers in the early spring and Lactuca Canadensis over here flowers in summer. Similarly, flowers that open up in the night never fertilize by flowers that open during the day. |
|
|
Term
|
Definition
| These Galapagos blue footed boobies only after a very much extended male display. You can see here the male is lifting his beautiful very, very lovely blue feet in this sort of high stepping motion shows off the color, shows off how vigorous he is, how strong, how healthy. Related boobies on the Galapagos like these red footed ones have a different mating ritual and different colored feet. This nice arching neck activity here although the placement of the branch of those beautiful red feet still shows them off. Any difference in mating display, different songs, different dances, different waggles |
|
|
Term
|
Definition
| In some flowers the differences in the proportional flower structures among related species limit pollinators’ ability to transfer pollen to the wrong species,When a physical difference between different species prevents the transmission of gametes |
|
|
Term
|
Definition
| Here chemical ques that typically animate from the egg fail to attract sperm and actually prevent fertilization effectively blocking sperm from another species from penetrating the egg.is extraordinarily common in species like these abalone here that directly release their gametes into the water or into the air. Those gametes that are being released better have a good way to meet up with the right partner and not waste their effort in gametes on from another species. |
|
|
Term
|
Definition
| Typically when two different species cross the resulting embryo will not develop or if it’s born it will not survive to adulthood that is it will not survive to reproductive maturity itself. |
|
|
Term
|
Definition
| . However, some hybrids do survive and these themselves are usually infertile. So, they can survive to adulthood, but they cannot produce offspring themselves. |
|
|
Term
|
Definition
| case with the liger that I talked about earlier. The liger survived, it’s fertile but its offspring are infertile and we call this kind of post-zygotic isolation |
|
|
Term
|
Definition
| this is when a speciation event is started by an event that should be familiar to you it’s like a Founder effect which can lead to genetic drift. We believe this is the source of all the species can occur on the Galapagos: turtles, tortoises, iguanas, finches, mockingbirds etc., so this when a small group of individuals leave a big population and start the new population somewhere else. |
|
|
Term
|
Definition
| This is where a geographical barrier pops up splitting an ancestral population into two and in this figure we use to have interbreeding population of beetles but now there is a river that flows between the middle of the population and the beetles can no longer interbreed giving that the beetles don’t swim very well. The most famous example for vicariance isolation is the movement of plates on Earth which has led to the splitting of populations as continents drifted apart and in great example of this sort of vicariance comes from cycads. |
|
|
Term
|
Definition
| in this case you have a chain of separated populations, say this pine trees here in the valley between these two mountain ranges and there close enough to each other that individuals or gametes can move in between the two intervening populations but let’s say one intervening populations goes extinct there’s a small forest fire or a pine tree disease that knocks out this whole population. Once that intervening population goes extinct the remaining individuals cannot move from these end populations to the other and that effectively cuts off the flow of genes between the remaining populations and they become effectively isolated from one another. |
|
|
Term
| How is continental drift related to speciation? |
|
Definition
| For a long time, the distribution of cycads on the planet were very confusing because they seem to span South America, Africa, India, and Australia. So, these are very distant parts of the world. That’s not confusing in general but very confusing when you find out that cycads seeds don’t float. So, how did they move all over the place being such an old lineage? That was very confusing, we didn’t have people in boats moving them around. However, it’s been determined from using genetic analysis that this group plants arose before the break up of one of the first 2 super continents that’s Gondwanaland. So when Pangea, the first super continent, broke in half the southern continent was Gondwanaland and current populations of cycads are all on pieces of what was Gondwanaland. So there’s been a very few that’s snaked up through the Panama Canal which forms the land bridge between North and South America. Now however these populations of cycads on these different continents are very, very different. They are very separated by the intervening oceans and that has allowed evolution to take very different paths on the different continents. |
|
|
Term
|
Definition
| There are a number of cases that are really hard to interpret any other way. There’s a lake in Cameroon, Lake Barombi Mbo it is extremely small and therefore very homogeneous there is not a lot of opportunity for it to subdivided the lake by area or any other way and yet there are 11 different species of cichlid fish that are in this lake that are most related to each other than any other species from outside the lake. |
|
|
Term
|
Definition
| This tetraploid can self-fertilize, if it’s a plant or can cross with other tetraploids but it cannot mate with its parental species. So, in a single meiotic event the new species could be created that is highly viable. As I’ve said this happens very regularly in plants, but it’s also been seen in animals as well. But it turns out this gets at something that I’ve talked about last Wednesday polyploidy is not the only possibility for sympatric speciation. |
|
|
Term
| How might disruptive selection lead to sympatric speciation? |
|
Definition
| Especially when combine disruptive selection with large amounts of assortative mating. So let’s think about this lets say there are two divergent phenotypes that are being selected for and for whatever reason the individuals involved are more likely to mate with like individuals either because they don’t encounter different individuals than themselves or they have a preference to similar mates, right. This leads to assortative mating. Then despite the two groups are in close proximity there capable of exchanging genes, the populations effectively become separated and the same processes that could occur in allopatry and can occur in sympatry. |
|
|
Term
|
Definition
| one species go to multiple species because of resources.We think this is most likely to happen when the new environment contains relatively few species an environment like a volcanic island chain, like the Galapagos. Volcano forms an island in the middle of the ocean and it starts with nothing there but as species migrate onto the island they get more and more resources that no one is necessarily using to begin with. So, early evolution on volcanic islands can be very rapid and very extreme. |
|
|
Term
|
Definition
| different species can mate, children can also have children and this goes on and on and on. (rat snakes) |
|
|
Term
|
Definition
| type of salamanders that are in south cali that move up and then go down(in a circle). Once they go around the circle they can not reproduce with the salamanders that just started in the circle because so much evolution during time at the end of circle. |
|
|
