Descent From Teosinte Hypothesis
The “Descent from Teosinte” hypothesis helps define the difference between maize and teosinte. According to Iltis, corn is cultivated teosinte, they do not differ in genetic or vegetative features (Goodman, 1988). Human select qualities in corn that produce more food, larger quantity, and efficient yield. Maize and teosinte have the same amount of chromosomes and similar structure due to common descent. At the DNA level, teosinte and maize have the same number of chromosomes and almost the same arrangement of genes. George Beadle, was the first scientist to study maize-teosinte hy-birds (“Evolution of Corn”). Beadle found that maize and teosinte are different in about 5 genes, by using laws of genetic inheritance (“Evolution of Corn”). Beadles
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significant finding was supported by another group of scientists that also analyzed the DNA of maize and teosinte. They also found that there were about 5 sections in the genome that controlled their differences (“Evolution of Corn”).
Maize is unique from teosinte in the following features: different amounts of cupule pressed cause rigid rachis, kernels are surrounded by glumes, ear has husks (Goodman, 1988).
The genetic differences between teosinte and corn include branching, ear structure, fruitcase, and seed structure. Corn branches up as a single stem with ears while teosinte is branched and has many ears. Corn has an average of 10 rows of seeds and teosinte has two rows. The teosinte fruit produces a seed due to one of the paired seeds (spike is terminated) and in corn both spikes are fertile (“Evolution of Corn”). In seed structure, teosinte seed is covered by a hard fruitcase, and in corn the furitcase is decreased and forms into the corn cob (“Evolution of Corn”). Although maize and teosinte have some unique characteristics, it is proved that teosinte is the common ancestor or …show more content…
maize.
Evolutionary Applications in Agriculture Evolutionary principles are a important in agriculture and environmental science. For example, evolutionary principles help aim design methods to slow down evolution of weeds, pests, or pathogens that prevent increasing crop yield or quantity (Hendry, 2011). Phenotypic variation is important in agriculture because it is based off of genetic and phenotypic differences. Quality and quantity are essential in agriculture, and it is seeked by finding the perfect environmental conditions, manipulating fertilizers, water, or pesticides (Hendry, 2011).
The Illinois maize experiment by Moose et.
al (2004), studied changes in protein from artificial selection in a maize selection experiment. This experiment compared generation vs. percent of both protein and oil. The results concluded there was a “dramatic” change, more than 20 standard deviations from the original population mean the positive direction and 4 in the negative direction (Hendry, 2011). Hendry believes that it may be due to standing genetic variation. The traits may have been altered by countless alleles and loci, and selection on each allele was uncertain, and recombination allowed for new variation (Moose et. al 2004). Thus, artificial selection of high protein for example, may not represent
evolution.
Humans fix genetic variation to achieve large reproductive outcomes. It is achievable because humans benefit the reproduction of desired crop and provide desirable conditions, and deleterious mutations were most likely removed through selection and bottlenecks (Hendry, 2011). Humans select according to genotypes and phenotypes that provide high fitness compared to others. Generally, inbreeding lessens a population’s average fitness.
Selection in agriculture is controlled by humans, it may help or harm agriculture. Humans want to achieve high yield, but this can lead to individual competitiveness (Hendry, 2010). For example, Hendry states that competition between individual plants may favor large roots and leaves, however, population level productivity is at intermediate root and leaf size (Hendry, 2011). He believes that trade-offs may improve breeding and cultivation in evolutionary developments in yield. Human activity causes changes in the environment, therefore it establishes a strong selection.
Inclusive Fitness in Agriculture The objective of agriculture is to raise productivity, regardless of the cost it may have on individual fitness. Previous evolutionary crops were directed by individual fitness (Kiers, 2014). Human breeders are capable of selecting the desired characteristics that increase crop output, at the risk of their individual fitness. There are possible conflicts among individual plant fitness and community productivity. For example, Kiers et al. suggest that increasing resources costs neighboring plants, therefore it lowers the total crop yield. Thus, seed production is important to crop yield and individual fitness (Kiers, 2014). There is a possibility that human plant breeders could create crops with higher efficient resources unnoticed by previous natural selection due to trade-offs by individual corn competitiveness (Kiers, 2014). Inclusively, increasing individual fitness does not always maximize individual competitiveness (Kiers. 2014). Strong selection for traits are selected by humans and they can incorporate community level advantages, unlike nature. Overall, increasing crop yields solely sacrifices individual fitness (Kiers, 2014).
Conclusion
Agriculture essentially provides food supply for humans and livestock around the world. It is incredible how humans utilize evolutionary processes for advantages and select desired outcomes of crops such as corn. Overall, evolution plays a key role in agriculture.
significant finding was supported by another group of scientists that also analyzed the DNA of maize and teosinte. They also found that there were about 5 sections in the genome that controlled their differences (“Evolution of Corn”).
Maize is unique from teosinte in the following features: different amounts of cupule pressed cause rigid rachis, kernels are surrounded by glumes, ear has husks (Goodman, 1988).
The genetic differences between teosinte and corn include branching, ear structure, fruitcase, and seed structure. Corn branches up as a single stem with ears while teosinte is branched and has many ears. Corn has an average of 10 rows of seeds and teosinte has two rows. The teosinte fruit produces a seed due to one of the paired seeds (spike is terminated) and in corn both spikes are fertile (“Evolution of Corn”). In seed structure, teosinte seed is covered by a hard fruitcase, and in corn the furitcase is decreased and forms into the corn cob (“Evolution of Corn”). Although maize and teosinte have some unique characteristics, it is proved that teosinte is the common ancestor or …show more content…
maize.
Evolutionary Applications in Agriculture Evolutionary principles are a important in agriculture and environmental science. For example, evolutionary principles help aim design methods to slow down evolution of weeds, pests, or pathogens that prevent increasing crop yield or quantity (Hendry, 2011). Phenotypic variation is important in agriculture because it is based off of genetic and phenotypic differences. Quality and quantity are essential in agriculture, and it is seeked by finding the perfect environmental conditions, manipulating fertilizers, water, or pesticides (Hendry, 2011).
The Illinois maize experiment by Moose et.
al (2004), studied changes in protein from artificial selection in a maize selection experiment. This experiment compared generation vs. percent of both protein and oil. The results concluded there was a “dramatic” change, more than 20 standard deviations from the original population mean the positive direction and 4 in the negative direction (Hendry, 2011). Hendry believes that it may be due to standing genetic variation. The traits may have been altered by countless alleles and loci, and selection on each allele was uncertain, and recombination allowed for new variation (Moose et. al 2004). Thus, artificial selection of high protein for example, may not represent
evolution.
Humans fix genetic variation to achieve large reproductive outcomes. It is achievable because humans benefit the reproduction of desired crop and provide desirable conditions, and deleterious mutations were most likely removed through selection and bottlenecks (Hendry, 2011). Humans select according to genotypes and phenotypes that provide high fitness compared to others. Generally, inbreeding lessens a population’s average fitness.
Selection in agriculture is controlled by humans, it may help or harm agriculture. Humans want to achieve high yield, but this can lead to individual competitiveness (Hendry, 2010). For example, Hendry states that competition between individual plants may favor large roots and leaves, however, population level productivity is at intermediate root and leaf size (Hendry, 2011). He believes that trade-offs may improve breeding and cultivation in evolutionary developments in yield. Human activity causes changes in the environment, therefore it establishes a strong selection.
Inclusive Fitness in Agriculture The objective of agriculture is to raise productivity, regardless of the cost it may have on individual fitness. Previous evolutionary crops were directed by individual fitness (Kiers, 2014). Human breeders are capable of selecting the desired characteristics that increase crop output, at the risk of their individual fitness. There are possible conflicts among individual plant fitness and community productivity. For example, Kiers et al. suggest that increasing resources costs neighboring plants, therefore it lowers the total crop yield. Thus, seed production is important to crop yield and individual fitness (Kiers, 2014). There is a possibility that human plant breeders could create crops with higher efficient resources unnoticed by previous natural selection due to trade-offs by individual corn competitiveness (Kiers, 2014). Inclusively, increasing individual fitness does not always maximize individual competitiveness (Kiers. 2014). Strong selection for traits are selected by humans and they can incorporate community level advantages, unlike nature. Overall, increasing crop yields solely sacrifices individual fitness (Kiers, 2014).
Conclusion
Agriculture essentially provides food supply for humans and livestock around the world. It is incredible how humans utilize evolutionary processes for advantages and select desired outcomes of crops such as corn. Overall, evolution plays a key role in agriculture.