James Linzel's List: Climate Change

• would increase their survival by decreasing their visibility from predators. Eventually, through the progression of time, the spontaneously mutated traits’ comparative advantage becomes so distinct that all lizards in that given ecomorph bears the phenotype; either by inheritance or because of the low survival rate accompanying the lack of said phenotype . Genetic diversity is decreased. Gene flow between existing groups decreases as well as the disruptive selection continues.

  • Need to use a more complete description of the process using terms such as: competition, mutation, phenotype, selection, etc...
• reproductivity

• Because dewlaps reflect light in a given environment, it is favorable for A. Cristatellus to have brighter dewlaps to be more visually noticeable by prospective mates in their given shady niche.

   

  Although A. cristatellus and A. cooki live in the same environment, because of the different niche that they inhabit,  they have different dewlap colors. This difference serves as a reproductive isolation mechanism between the two species because female lizards tend to target a very specific dewlap color as an indication of genetic similarity. Slowly there would be none or decreased gene flow between the two species.

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• Natural selection determines who lives and who dies
• After a long time the natural selection could have cause a directional selection which shift the population of bush lizards to on average being smaller.
• physic
• he p-value is 0.0009 which means that the data is very strong.
• This isolation is where the women need to be able to see dewlap and so if the dewlap is dark in a dark area the women would not be able to see it where as if it was dark in a light and sunny enviroment. The environment then choose who will mate and who will not. This leads to men with bright mating with women in dark areas and men with dark more likely to mate in light sunny areas.

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• ue to the adaptations they made for the different foods they at
• ht have mutated to adapt to their environment
• Species need to reproduce, find food and survive through natural selection,
• n, because without those random mutations, species would not be able to change physically, and ultimately will not be able to survive. In the case of the Galapagos Finches, they adap

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• mutation within its genes that was favorable (i.e. more toe pad lamellae that allowed it to cling to a tree), survived, and passed the trait on to its offspring.
• ates variation w
• (the ratio of mtDNA in an egg versus a sperm is 100,000:100
• o correct any errors within the sequence
• perfect
• needs c
• The tree suggests that the islands of Hispaniola and Puerto Rico have similar ecologies because the lizards evolved to extremely similar ecomorphs.
• weight
• rence is not due to chance and that there is likely an actual distinction.
• Where long legs are better for easy navigation through the tall trees on Iron Cay, short legs are favorable on the experimental islands for narrow bushes and fast movement on the ground.
• he population is small, it might be hard for a female to come across a mate within its surroundings and the males who stand out will be easier to find. The A. cristatellus species lives in a shady, forest environment and with a bright dewlap (average of 4.9) it will stand out. Vice versa for the A. cooki who resides in a sunny environment with a darker dewlap color
• e, the extremes within each scenario (the brightest or the darkest) are more likely to reproduce than the average which causes directional selection. The colors of the species will continue to differ until it reaches reproductive isolation and if two lizards – one from each species – were to meet, they would not consider the other as a possible mate (prezygotic isolation). If by chance they were to mate, if the species had changed enough (not only the dewlap color but the accumulation of other adaptio

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• s to migrate to
• mtDNA is so crucial to an organism’s being alive that mutations to it would probably be fatal. Therefore, mutations occur at a slower rate.
• Therefore, mtDNA serves as a molecular clock for dating divergence–it can be used to estimate when two species split off from a common ancestor by examining the base pair differences in the mtDNA sequence.
• The P-value of a t-test tells me whether the probability that the observed difference is a true difference or if it occurred by chance.
• This P value of 0.0005 means that there is only a 0.05% chance that the difference in the average relative hindlimb length of the two populations occurred by chance and that there is a 99.95 percent chance that there IS indeed a difference
• therefore, males with brighter dewlaps are more likely to mate and reproduce in a dark environment
• Therefore, gene flow between the two populations is inhibited and the single anole specie will diverge into two new species since the two populations will not mate with each other or be able to produce fertile offspring.

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• selected in or selected out
• een selected for its short legs in an environment consisted of numerous twigs and bushes. This gives these lizards an advantage, because with the short legs, there are able to quickly and efficiently move through the twigs and bushes, whereas if they were equipped with longer legs, it would have been harder to do so. On the other hand, the A. cristatellus, A. evermanni, and A. coelestinus lizards, which are categorized with the Trunk-Ground niche, might have been selected for their long legs, enabling them to run away faster from approaching predators on ground. Also, the lizards with the Trunk-Crown niche, gradually adapted to the high, leafy tree trunks, enabling them to be equipped with large toe pads. This can be seen in the case of the A. evermanni and A. Coelestinus lizards. The reason why the lizards are being inhabited with differing n
• contain much more genetic information than do the genes for the specific traits measured in this experiment.
• This allows biologists to elucidate the evolutionary relationships of species more efficiently and clearly than if the genes for the traits were measured.
• chondrial DNA, there is usually no change in the DNA from parent to offspring, enabling it to be only from the mother’s side.
• proves
• 014. In other words, it could be confidently stated that the lizards living on Iron Cay indeed, had longer relative Hindlimb than the lizards living on the experimental island, and that this result didn’t just come about due to random chance. Nevertheless, the results would have been more confident if more than 10 lizards were observed in an island.
• ecause the A. cristatellus adapted to have brighter dewlaps to attract the females in shady forests. On the other hand, the A. cooki lizards, which live on a sunnier environment, adapt to darker shaded dewlaps to stand out from the environment they are placed in. This is the case of reproductive isolation, where the female lizard will not perceive the male lizard with the varying colored dewlap to be part of the same species, and thus will not reproduce with the male. As time passes, the lizards with darker dewlaps in sunnier environment will vary even more form the lizards with lighter dewlaps in shadier environments. Thus, eventually the two species will be even more reproductively isolated than now. Also, ev

  • All good. Think about - REDUCTION in gene flow over time. Even though the dewlaps are diverging it does not mean ZERO reproduction between the two groups. 

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• .The variation that drove these lizards to be drastically different from each other is caused by random mutation or recombination in the lizard’s genetic sequence that occurred many years ago.
• It became apparent that lizards with shorter legs lived in higher settings and lizards with longer legs lived in lower habitats.
• Adaptations are when species fit and alter to an ecological change.
• These lizards will then pass on their mutations to their offspring, and long legs, which were what saved their lives, will become their adaptation. Mutations aren’t necessarily always good or bad. Going back to the flood example, a lizard with the mutation of extremely long legs wouldn’t have survived the situation. Given that some species that live on broader surfaces have longer legs, and others that live on twigs have shorter legs, each ecomorphs specialize for a certain habitat. This phenomenon is called divergent evolution
• tRNAs have an anti-codon that acts as a repair mechanism
• The rate of change in really important proteins is really slow,
• On the contrary, lizards from the same island are more closely related to one another than to similar looking lizards from other island
• nt, is known as adaptive radiation
• their adaptation
• eeing that the P value for the data was 0.0004, this small p-value provides strong evidence against the null hypothesis (which claims that there is no difference between specified populations)
• However, the level of confidence in the degree of adaptation over the time period is fairly low
• It will also increase if the experiment was repeated several more times with larger number of lizards.
• will only be attracted to m

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• Question

   

  Why and how did the numerous species of anoles evolve in these island regions?
• e conclusion is that the same ecomorphs of anole lizards evolved independently on different islands.
• Anolis cristatellus evolved to have long legs to remain stable and move faster on tree trunks.
• s cancelled out f
• canceled out
• nerally, a P-value that is less than 0.05 is considered to be statistically significant. Thus, the P-value for this lab is statistically significant as it is extremely small.
• t” (Graphpad.com). The 95% confidence interval of this value ranges from 0.01455 to 0.08945. The fact of this lab is that only 10 lizards were used to measure the hind limbs, which is difficult to generalize to the whole population of islands in Iron Cay. In addition, we should not forget to consider the duration of this field experiment. If the difference in mean between the two islands was 0.05700 in this relatively short period of time, the difference would be much larger if this experiment was taken for a longer period of time.
• s highly possible that a gene flow occurs
• According to Bailey, a population with genetic variation is more able to adapt to their environments than those without genetic variation (Bailey).

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