Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others.
What does Darwin say about variation in domesticated species?
Darwin notes that there is greater variation observed in domesticated species than would be seen in the wild. There is the belief that this could be caused by variations in climate, treatment or an excess of food, but Darwin sees these factors as being...
Is domestication natural selection or artificial selection?
Domestication in these cases is a mixture of artificial selection (both weak and strong) for favorable traits and natural selection for adaptation to captivity, with artificial selection being the prime mover. TABLE 5.2 Favorable and Unfavorable Ecological and Behavioral Pre-adaptations to Domestication.
What is artificial selection in human evolution?
Artificial selection is the selection of advantageous natural variation for human ends and is the mechanism by which most domestic species evolved. Most domesticates have their origin in one of a few historic centers of domestication as farm animals. Two notable exceptions are cats and dogs.
What is the first chapter of the origin of species about?
The Origin of Species Summary and Analysis of Chapter 1- Variation Under Domestication. In this first chapter Darwin begins his investigation by looking at domesticated plants and animals. Darwin notes that there is greater variation observed in domesticated species than would be seen in the wild.
What is the mechanism by which most domestic species evolved?
When was natural selection first described?
How did barnyard animals become domesticated?
What is the process of domestication of wildcats?
When did wildcats start domesticating?
What is the purpose of Darwin's Variation of Animals and Plants Under Domestication?
What were the consequences of domesticating animals?
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From wild animals to domestic pets, an evolutionary view of ...
Darwin famously first described natural selection in 1859 with his classic monograph On the Origin of Species.Sexual selection was addressed in Descent of Man, and Selection Related to Sex in 1871. In between those two, in 1868, Darwin published a 2-volume work, The Variation of Animals and Plants Under Domestication, in which he expands upon a third distinct stream of evolutionary mechanism ...
How Do Animals Benefit From Domestication? - WorldAtlas
Domestication refers to the process of adapting plants and animals from the wilderness for human use. These species get used for work, food, clothing, medicine, and many other things. Of course, we will be dealing with animals, specifically in this article, and if domestication can benefit them in any way.
How does natural selection affect the variation of a species?
Thus, organisms fight for every-day needs and a competition for limited resources ensues. Furthermore, natural selection also explains the variation of a species. Darwin observed that members of a population frequently differ in physical traits, traits inherited from parents to offspring. Individuals with better adapted physical traits are more likely to survive and reproduce, thereby giving genetic duplicates to the next generation. Individuals who are best adapted to the environment survive while individuals who are least adapted to the environment become extinct.
What is the chapter 1 of Variation Under Domestication?
Variation Under Domestication Charles Darwin Traveled all around the world observing nature and each different species of animals and plants and got to the conclusion that almost every part of each individual are incredibly related to the difficult or peculiar conditions of life.
Why is natural selection important?
Darwin’s natural selection theory is the most successful one because of the collected data and examples given to back up his theory. In other scientific researches, it is said that natural selection is not the only cause of evolution. Darwin even said himself, "The natural selection is an important cause of variation but not its sole reason."
What is the theory of evolution?
What Darwin means by that is that as the descendants of a certain species spread out over vast regions of the Earth , each descendent develops numerous modifications and changes to either its appearance or its mental appearance. Those adaptations and changes help those animals thrive in the ecosystem/habitat that they live in. Without those changes, these animals cannot survive from their predators and the natural threats that they may face on a day-to-day basis.
Why is Darwin's belief that there is greater variation observed in domesticated species than would be seen in the wild?
There is the belief that this could be caused by variations in climate, treatment or an excess of food, but Darwin sees these factors as being insufficient. He notes that if this were true would have to be exposed to these factors ...
How do domesticated species change?
Domesticated species are also effected by unconscious selection where small changes, often unnoticed at first accumulate over generations. Some changes may be cosmetic, while others may be physical, but the effect of those changes in times of hardship or famine will help some of the species survive and pass on those traits to subsequent generations. In this way variations that at first may be unnoticeable may grow to the point of a new breed or subspecies.
What is the origin of species?
The Origin of Species Summary and Analysis of Chapter 1- Variation Under Domestication. In this first chapter Darwin begins his investigation by looking at domesticated plants and animals. Darwin notes that there is greater variation observed in domesticated species than would be seen in the wild.
How does conscious and unconscious selection affect species?
The cumulative effect of conscious and unconscious selection on species has led to more variation in domestic species than would be seen in the wild due to active and passive rolls in breeding to encourage or discourage certain traits.
What would happen if the environment was the primary cause of variation?
If environment were the primary cause of variation then definite changes in environment would cause definite changes in organisms which would proceed in a linear fashion through successive generations if the environmental factors remained constant.
What animal did Darwin study?
After looking at this through a number of different types of animals he has focused his study on domestic pigeons . Darwin goes into great detail describing the differences in various types of domesticated pigeons from their beaks, to bone structure from feathers to coloring and other features.
What is the mechanism by which most domestic species evolved?
Artificial selection is the selection of advantageous natural variation for human ends and is the mechanism by which most domestic species evolved. Most domesticates have their origin in one of a few historic centers of domestication as farm animals. Two notable exceptions are cats and dogs. Wolf domestication was initiated late in the Mesolithic when humans were nomadic hunter-gatherers. Those wolves less afraid of humans scavenged nomadic hunting camps and over time developed utility, initially as guards warning of approaching animals or other nomadic bands and soon thereafter as hunters, an attribute tuned by artificial selection . The first domestic cats had limited utility and initiated their domestication among the earliest agricultural Neolithic settlements in the Near East. Wildcat domestication occurred through a self-selective process in which behavioral reproductive isolation evolved as a correlated character of assortative mating coupled to habitat choice for urban environments. Eurasian wildcats initiated domestication and their evolution to companion animals was initially a process of natural, rather than artificial, selection over time driven during their sympatry with forbear wildcats.
When was natural selection first described?
Darwin famously first described natural selection in 1859 with his classic monographOn the Origin of Species. Sexual selection was addressed inDescent of Man,and Selection Related to Sexin 1871. In between those two, in 1868, Darwin published a 2-volume work,The Variation of Animals and Plants Under Domestication, in which he expands upon a third distinct stream of evolutionary mechanism—artificial selection—that he first had outlined inOrigin.
How did barnyard animals become domesticated?
Domestication of today’s barnyard animals proceeded as a result of pressure by these early hunter-gatherers as they intuitively sought to stabilize their food resources (Clutton-Brock, 1999; Zeder, 2006; Zeder et al., 2006b). Among the successful domesticates, most were behaviorally preadapted to domestication. Behavioral characteristics considered favorable and unfavorable are presented in Table 5.2. Barnyard animals descend from herd-living herbivores whose ancestors followed a dominant individual through a territory shared with other herds. Neolithic peoples exploited this dominance hierarchy by, in effect, supplanting the alpha individual and thereby gaining control of the herd. Herd-living animals were predisposed to tolerate close living quarters, and their temperament allowed them to adapt easily to confinement. They also had a flexible diet (enough to live on what early farmers might provide), grew fast (and thus did not unduly expend farmers’ resources), and would freely breed in the presence of people (Zeuner, 1963; Hemmer, 1990; Clutton-Brock, 1999). A comparison of the occurrence of preadaptive characters among wild species of the Fertile Crescent is presented in Table 5.3. The predecessors of today’s farm animals were undoubtedly selectively managed in hunts in natural habitats (corresponding to our weak artificial selection) before individuals were taken into captivity and bred (Darwin, 1890; Clutton-Brock, 1999; Zeder, 2006; Zeder et al., 2006b). Animals that bred well could then be selected (either consciously or unconsciously) for favorable traits (corresponding to our strong artificial selection). Domestication in these cases is a mixture of artificial selection (both weak and strong) for favorable traits and natural selection for adaptation to captivity, with artificial selection being the prime mover.
What is the process of domestication of wildcats?
Eurasian wildcats initiated domestication and their evolution to companion animals was initially a process of natural , rather than artificial, selection over time driven during their sympatry with forbear wildcats. Artificial selection is the selection of advantageous natural variation for human ends and is the mechanism by which most domestic ...
When did wildcats start domesticating?
The available archaeological evidence indicates that the process of wildcat domestication began in the Neolithic in the same place and time as the development of year-round settlements and the onset of an agricultural economy (Clutton-Brock, 1993; Vigne et al., 2004; Driscoll et al., 2007). As far as the local fauna was concerned, these permanent human settlements developedex nihilo. Opportunistic animals apparently ventured into this new urban environment, rich in food year-round and free of most predators, and found fertile new ecological niches to exploit (Zeuner, 1963; Coppinger and Smith, 1983). The ability to live around people therefore conferred important advantages to those animals that adapted to it (Morey, 1994). Commensal species such as mice, rats, and sparrows that adapted to human village environs (and their trash) probably emerged first. Although the earliest grain cache (of wild, not domestic, grains) in the Near East is dated to 21,000B.P.(Tanno and Willcox, 2006), the origin of agriculture per se in the region is dated to between 12,500 and 11,250B.P.(Hillman et al., 2001), and it is from approximately this period that house mice locally appeared (Auffray et al., 1988). Resident populations of peridomestic rodents sustained by trash dumps and stockpiles of grain provided a reliable food source for native wildcats, which then became adapted to an “urban” environment as peridomestic human commensals themselves (Serpell, 1990; Sunquist and Sunquist, 2002).
What is the purpose of Darwin's Variation of Animals and Plants Under Domestication?
Darwin’sThe Variation of Animals and Plants Under Domestication(Darwin, 1890) offers a litany of facts and examples of artificial selection in action at the hands of plant and animal breeders. Darwin felt that an understanding and appreciation of the depth of artificial selection was fundamental to the acceptance of natural selection. InVariation, Darwin wanted to expand on this artificial mechanism of evolution beyond examples inOrigin, where he describes familiar and tangible results of husbandmen in his argument that selection by the analogous natural means—survival of the fittest—was not just plausible or possible, but probable. Darwin considered any variety, breed, or subspecies, no matter how it was derived, as an incipient species, irrespective of the particular selective mechanism driving the group’s evolution (Darwin, 1890). He sought to illustrate that tremendous changes can be wrought through the “gradual and accumulative force of selection,” but he also emphasized that evolution by selection of any type can only work where variation is present; “[t]he power of selection … absolutely depends on the variability of organic beings” (Darwin, 1890). Thus, genetic differences between domesticates and their wild counterparts substantially reflect the native genetic variation (i.e., standing variation) present in the wild population before any selection (natural or artificial) for tameness, and the secondary effects of isolation (Darwin, 1890).
What were the consequences of domesticating animals?
The consequences for the planet (as well as for humanity and its domesticates) have been profound, and have included the complete transformation of almost every natural ecosystem on Earth. Domesticating animals and plants brought surpluses of calories and nutrients and ushered in the Neolithic Revolution.
