Unit 10 - Chapter 24 - The Origin of Species
Terms
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- paleontological species concept
- focuses on morphologically discrete species known only from the fossil record
- allometric growth
- the variation in the relative rates of growth of various parts of the body, which help shape an organism
- adaptive radiation
- the evolution of of many diversely adapted species from a common ancestor upon introduction to various new environmental opportunities and challenges is called____________ _________
- polyploidy
- some plant species have their origins in accidents during cell division that result in extra sets of chromosomes
- morphological species concept
- characterizes a species by its body shape, size, and other structural features
- Hox genes
- the products of one class of homeotic genes, called ______ _______, provide positional information in an animal embryo
- reproductive isolation
- the existence of biological factors (barriers) that impepde members of two species from producing viable, fertile hybrids
- ecological species concept
- views a species in terms of its ecological nich, its rule in a biological community
- allopolyploid
- in subsequenc generations, various mechanisms can change a sterile hybrid into a fertile polypolidy known as an _______________
- paedomorphosis
- if reproductive development accelerates compared to somatic development, the sexually mature stage of a species may retain body features that were juvenile structures in an ancestral species
- postzygotic barriers
- if a sperm cell form one species overcomes prezygotic barriers and fertilizes ana ovum from another species, _________ _________ often prevent the hybrid from developing into a viable, fertile adult
- phylogenetic species concept
- defines a species as a set of organisms with a unique genetic history
- species
- most often characterized by their physical form of morphology, although differences in physiology, biochemistry, behavior, and genetics support the existence of distinct species
- biological species concept
- defines a species as a population/group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring with members of other populations
- prezygotic barriers
- immpede mating between species or hinder the fertilization of ova when members of different species attempt to mate
- species selection
- a theory maintaining that species living the longest and generating the greatest number of species to determine the direction of major evolutionary trends
- allopatric speciation
- gene flow is interrupted with a population is divided into geographically isolated subpopulations
- sympatric speciation
- speciation takes place in geographically overlapping populations
- homeotic genes
- _______ ______ determine such basic features as where a pair of wings and a pair of legs will develop on a bird
- punctuated equilibrium
- in evolutionary theory, long periods of no change interrupted by relatively brief periods of sudden change
- autopolyploidy
- an ___________ is an individual that has more than 2 sets of chromosomes, all derived from a single species
- heterochrony
- an evolutionarya change in the rate or timing of developmental events