Community Disturbances and Stability Notes
... __________________________________ are the first species to live on bare rock. Lichens and mosses are examples of pioneer species. Each stage of succession supports different types of plants and animals. After hundreds of years, enough soil has been built up to support entire forests. This final sta ...
... __________________________________ are the first species to live on bare rock. Lichens and mosses are examples of pioneer species. Each stage of succession supports different types of plants and animals. After hundreds of years, enough soil has been built up to support entire forests. This final sta ...
File
... 1. Those with extremes of colour are best camouflaged, perhaps depending on the seabed (sand or rock). This can result in two forms that eventually follow two evolutionary paths and form new sub-species and then species. 2. Sometimes the average is best, providing optimum balance and therefore the m ...
... 1. Those with extremes of colour are best camouflaged, perhaps depending on the seabed (sand or rock). This can result in two forms that eventually follow two evolutionary paths and form new sub-species and then species. 2. Sometimes the average is best, providing optimum balance and therefore the m ...
Slide 1
... 1. Reinforcement of reproductive barriers = maintain two species 2. Weakening of the reproductive barriers = fusion of gene pools into one species 3. Stability = Hybrid individuals persist and thrive (not common) ...
... 1. Reinforcement of reproductive barriers = maintain two species 2. Weakening of the reproductive barriers = fusion of gene pools into one species 3. Stability = Hybrid individuals persist and thrive (not common) ...
Speciation
... Radiation • A single ancestral species gives rise to a variety of species, each adapted to a specific environment • Hawaiian honeycreepers • Occurred after dinosaur extinction mammals diversified in only 10 million yrs! ...
... Radiation • A single ancestral species gives rise to a variety of species, each adapted to a specific environment • Hawaiian honeycreepers • Occurred after dinosaur extinction mammals diversified in only 10 million yrs! ...
S-B-9-1_Principles of Natural Selection
... bushes, the longer-necked animals are better adapted and so compete well compared to their shorter-necked relatives. These animals live longer, through more breeding seasons, and so they can have more offspring. In the next generation, there are more long-neck genes than short-neck genes in the popu ...
... bushes, the longer-necked animals are better adapted and so compete well compared to their shorter-necked relatives. These animals live longer, through more breeding seasons, and so they can have more offspring. In the next generation, there are more long-neck genes than short-neck genes in the popu ...
Principles of Natural Selection-Teacher Version
... bushes, the longer-necked animals are better adapted and so compete well compared to their shorter-necked relatives. These animals live longer, through more breeding seasons, and so they can have more offspring. In the next generation, there are more long-neck genes than short-neck genes in the popu ...
... bushes, the longer-necked animals are better adapted and so compete well compared to their shorter-necked relatives. These animals live longer, through more breeding seasons, and so they can have more offspring. In the next generation, there are more long-neck genes than short-neck genes in the popu ...
Summary Variations in chromosome number, also called as
... organization resulting in chromosome doubling without cell division. Meiotic behaviour of autotriploids is irregular, whereas autotetraploids and autohexaploids ...
... organization resulting in chromosome doubling without cell division. Meiotic behaviour of autotriploids is irregular, whereas autotetraploids and autohexaploids ...
The Origin of Species
... Why speciation rates are often rapid in situations when adaptive radiation occurs or in times of ecological stress The connection between a change in gene frequency, a change in the environment, natural selection, or genetic drift and speciation ...
... Why speciation rates are often rapid in situations when adaptive radiation occurs or in times of ecological stress The connection between a change in gene frequency, a change in the environment, natural selection, or genetic drift and speciation ...
I have - kirstymacfie
... A group of species The evolutionary A systematic Single species with that have history of a group. change along a phenotypic descended from a geographic transect variation, that can common ancestor. in the frequency of interbreed with a genotype or the connected phenotype. neighbors but not distant ...
... A group of species The evolutionary A systematic Single species with that have history of a group. change along a phenotypic descended from a geographic transect variation, that can common ancestor. in the frequency of interbreed with a genotype or the connected phenotype. neighbors but not distant ...
conservation practices – key terms
... Artificial selection: selection by humans for certain traits. This can be intentional, for breeding purposes. When species are grown for a long time in cultivation, however, surviving plants may undergo unintentional selection for the growing conditions. The survivors among nursery-grown plants may ...
... Artificial selection: selection by humans for certain traits. This can be intentional, for breeding purposes. When species are grown for a long time in cultivation, however, surviving plants may undergo unintentional selection for the growing conditions. The survivors among nursery-grown plants may ...
Conserving biodiversity at the gene level – what does it mean
... the task of conserving plant genetic diversity and suggest how we might monitor progress towards better conservation outcomes. Strategies must address both species that are cropped or harvested, and wild species that occur in the ecosystem. In several cases the wild species deserving particular atte ...
... the task of conserving plant genetic diversity and suggest how we might monitor progress towards better conservation outcomes. Strategies must address both species that are cropped or harvested, and wild species that occur in the ecosystem. In several cases the wild species deserving particular atte ...
crop production, lec 11.
... Chromosomes do not get segregated at the time of meiosis, resulting in the production of diploid gametes, which on fusion give rise to polyploid plants. ...
... Chromosomes do not get segregated at the time of meiosis, resulting in the production of diploid gametes, which on fusion give rise to polyploid plants. ...
2. Notes
... • In sympatric speciation, a reproductive barrier isolates a subset of a population without geographic separation from the parent species • Sympatric speciation can result from polyploidy, natural selection, or sexual selection ...
... • In sympatric speciation, a reproductive barrier isolates a subset of a population without geographic separation from the parent species • Sympatric speciation can result from polyploidy, natural selection, or sexual selection ...
Unit 7 Chapter 16 Part 2
... • For animals that use internal fertilization, the sperm of one species may not be able to survive the internal environment of the female reproductive tract of a different species. • Molecular gamete recognition ...
... • For animals that use internal fertilization, the sperm of one species may not be able to survive the internal environment of the female reproductive tract of a different species. • Molecular gamete recognition ...
Evolutionary Biology Key Terms
... Speciation -‐ the evolution of a new species that occurs when two similar reproducing beings evolve to become too dissimilar to share genetic information or produce viable offspring. species -‐ a gr ...
... Speciation -‐ the evolution of a new species that occurs when two similar reproducing beings evolve to become too dissimilar to share genetic information or produce viable offspring. species -‐ a gr ...
Untitled
... After it occurs, the same X is inactivated in mitotic daughter cells. X-inactivation preferentially affects the X from the father. X-inactivation occurs at the time of meiosis. One Y in an XYY individual is also inactivated. ...
... After it occurs, the same X is inactivated in mitotic daughter cells. X-inactivation preferentially affects the X from the father. X-inactivation occurs at the time of meiosis. One Y in an XYY individual is also inactivated. ...
Elegantní dopis
... 1) May we call the strain B6-XPWDBB6 consomic when the X chromosome is recombinant? Why a strain with intact PWD and B6 X chromosomes was not used in the cross? 2) According to the thesis, hybrid females displayed about 50% incidence of abnormalities in the pachytene stage relative to males. Can thi ...
... 1) May we call the strain B6-XPWDBB6 consomic when the X chromosome is recombinant? Why a strain with intact PWD and B6 X chromosomes was not used in the cross? 2) According to the thesis, hybrid females displayed about 50% incidence of abnormalities in the pachytene stage relative to males. Can thi ...
Allele Frequency, Gene Pools, and Species Variation
... Population X consists of a group of hares (rabbits) that are genetically similar. Population Y consists of a group of hares (rabbits) that are genetically varied. If they both live in the same habitat and something changes in their habitat, which population is more likely to survive? Explain. ...
... Population X consists of a group of hares (rabbits) that are genetically similar. Population Y consists of a group of hares (rabbits) that are genetically varied. If they both live in the same habitat and something changes in their habitat, which population is more likely to survive? Explain. ...
Evolution
... The genes themselves do not change or blend during reproduction If chromosomes and loci of the male and female do not match perfectly, reproduction cannot occur (prevents interbreeding) Offspring will resemble parents because genes must match at each locus, but the offspring will differ from both pa ...
... The genes themselves do not change or blend during reproduction If chromosomes and loci of the male and female do not match perfectly, reproduction cannot occur (prevents interbreeding) Offspring will resemble parents because genes must match at each locus, but the offspring will differ from both pa ...
Lecture #11 Date
... 2. Postzygotic barriers: fertilization occurs, but the hybrid zygote does not develop into a viable, fertile adult • Reduced hybrid viability (frogs; zygotes fail to develop or reach sexual maturity) • Reduced hybrid fertility (mule; horse x donkey; cannot backbreed) • Hybrid breakdown (cotton; 2nd ...
... 2. Postzygotic barriers: fertilization occurs, but the hybrid zygote does not develop into a viable, fertile adult • Reduced hybrid viability (frogs; zygotes fail to develop or reach sexual maturity) • Reduced hybrid fertility (mule; horse x donkey; cannot backbreed) • Hybrid breakdown (cotton; 2nd ...
Hybrid (biology)
In biology a hybrid, also known as cross breed, is the result of mixing, through sexual reproduction, two animals or plants of different breeds, varieties, species or genera. Using genetic terminology, it may be defined as follows. Hybrid generally refers to any offspring resulting from the breeding of two genetically distinct individuals, which usually will result in a high degree of heterozygosity, though hybrid and heterozygous are not, strictly speaking, synonymous. a genetic hybrid carries two different alleles of the same gene a structural hybrid results from the fusion of gametes that have differing structure in at least one chromosome, as a result of structural abnormalities a numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes a permanent hybrid is a situation where only the heterozygous genotype occurs, because all homozygous combinations are lethal.From a taxonomic perspective, hybrid refers to: Offspring resulting from the interbreeding between two animal species or plant species. See also hybrid speciation. Hybrids between different subspecies within a species (such as between the Bengal tiger and Siberian tiger) are known as intra-specific hybrids. Hybrids between different species within the same genus (such as between lions and tigers) are sometimes known as interspecific hybrids or crosses. Hybrids between different genera (such as between sheep and goats) are known as intergeneric hybrids. Extremely rare interfamilial hybrids have been known to occur (such as the guineafowl hybrids). No interordinal (between different orders) animal hybrids are known. The third type of hybrid consists of crosses between populations, breeds or cultivars within a single species. This meaning is often used in plant and animal breeding, where hybrids are commonly produced and selected, because they have desirable characteristics not found or inconsistently present in the parent individuals or populations.↑ ↑ ↑ ↑