As Allendorf and Hard’s review include alteration

As
humans continue to advance technologically, scientifically, and industrially,
there are inadvertent consequences posed to the evolution of other species. As
a species, human progression has had a tremendous impact both indirectly and
directly on the evolution of other species and has disrupted the ecological
balance of Earth. Through manmade issues such exploitation of natural
resources, domestication of animals and behaviors resulting in environmental
change humans have thrived in expanding as a population but have altered
long-term evolutionary biology as well. This response from other species and
ecosystems has called for drastic modifications on how humans interact with the
natural world.

            Harvesting animals that are
phenotypically desirable from wild populations is a process known as artificial
selection, which in long-term can result in the reduction in frequencies of
those selected phenotypes. This process that eventually evolves against
desirable phenotypes is known as unnatural selection Artificial selection and
breeding are examples of humans deliberately modifying species to fit their
requirements, whether it be animal companionship and domestication or food
purposes. Fred Allendorf and Jeffrey Hard’s review on human-induced evolution
caused by unnatural selection calls for those managing harvesting and wildlife
to implement responsible methods that take into account the induction of selective
effects and help avoid over-exploitation of wild populations.

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            Not only have there been phenotypic
modifications in response to selective pressures, but effects on sexual
selection and mating systems as well. This review discusses Darwin’s views on the
process of methodological, unconscious, and natural selection on domesticated
animals and plants but not on wild populations because it is something that has
been introduced relatively recently. However, in the rather short amount of
time humans have spent modifying selection in their favor, numerous
unintentional consequences have appeared in the biosphere.

            Since the late 19th
century, fishing and hunting have contributed to fulfilling humans expansive
diet, and with a rapid human growth rate these methods along with other food
harvesting techniques have resulted in exploitation of various species used to
feed the population.  The three genetic
consequences identified in Allendorf and Hard’s review include alteration of
population structure, loss of genetic variation, and evolution resulting
selection. Population characteristics that can affect genetic variability are
breeding population size, generation length, adult longevity, and mating
structure. Phenotypic alterations in these characteristics in response to over-harvesting
are shown to occur faster than in natural systems, meaning that sustainability
in food production must be taken into account and made a priority to slow down
these processes and mitigate rapid genetic change. In terms of food production
impacts on species, strategies can be implemented that focus on sustainable harvest,
detecting sensitive traits susceptible to genetic change, and proper recovery
systems to prevent Darwinian debt in populations throughout generations.

            The evolutionary arms race is the
concept of perpetual struggle between co-evolving species in which they develop
counter-adaptations against each other as a method of survival in the
environment they both inhabit. Stephen Palumbi explains that humans are the
world’s greatest evolutionary force primarily because we control change in
aspects such as disease and agriculture in our own species and in others. While
we can more easily see the effects of human ecological impact on larger species
and in the environment, small but numerous organisms such as bacteria and
insects are also involved in the evolutionary arms race as they counter adapt
to human progression in medicine and chemical use in agricultural practices. Palumbi’s
article discusses multiple cases of disease and insect resistance such as “treatments that used to require small
antibiotic doses that now require huge concentrations or demand powerful new
drugs” to compete with methicillin-resistant infections in humans (Palumbi, 2001). This rapid evolution driven by humans
also impacts insect species due to their increasing resistance to insecticides
used in farming that were initially effective. These resistance rates have
evolved in such a way that species that have become resistant to antibiotics
and pesticides have also evolved out of humans’ control.

            This not only affects the health of
various species involved, but also alters the economic aspect of human-induced
evolution. Loss of control in how organisms evolve in response to human activity
is costly as money is spent in developing counter methods to combat their
adaptations. This interaction exemplifies how extensive the effects of the arms
race between humans and other organisms has become. These expenses are
necessary in expanding human medicine and ensuring survival of the human
population, but are challenged by the ever-increasing responses from various
diseases and animal species seeking to maintain their survival as well.

            With the inevitable arms race
between humans and organisms that affect our health, Palumbi introduces
numerous methods innovated to slow down the pace of evolution that we are
responsible for influencing. These strategies are mainly produced through trial
and error, including methods such as drug overkill to reduce fitness variation
in infectious disease and pest management, direct observation therapy in
disease treatment to prevent epidemics, and screening for resistance to slow
down evolutionary mechanisms. The factors that manipulate changes in evolution
are being altered by human-mediated methods and through comprehensive prediction
and planning for these impacts, it is possible to lessen the effects they have
on the ecosystem.

            The human species has established
settlements and extended to areas of the Earth in a more widespread manner than
any other species, and continues to expand both terrestrially and aquatically.
Alexis Sullivan, Douglas Bird and George Perry discuss how the effects of human
advancement such as landscape modification have become a long-term ecological
driver of non-human evolution. Documentation of phenotypic modification such as
changes in body size and other major physical traits of various species in
response to human mediated selective pressures demonstrate the history of human
intervention with the biosphere. In a study of cliff swallows in Nebraska,
bridge and road construction resulted in the “overall population wing length decreasing ?2% across a 30-year period, probably because shorter wings
aided flight agility and reduced vehicle collision risk” (Sullivan, Bird, Perry,
2017). This is an example of the physical modifications in
non-human species in response to human habitat development. Similar to Palumbi’s discussion regarding
the relationship between agricultural development and the evolutionary arms race,
this review explains how habitat fragmentation has driven issues such as
climate change, population decline in wildlife, and extinction as a consequence
stemming from the process of sustaining the human population.

            Habitat modification has had major effects
on the trophic interactions between humans and the environment. As a keystone
species, humans are major influencers in how other species associate with the
environment and each other. Natural ecosystems have become unbalanced due to
problems like over harvesting and human overconsumption of meat dating back to
the existence of African hominins at least 2.5 million years ago. Long-term human disruption
has given rise to the term “hyper keystone species” to describe humans and supports
the “mounting evidence that prehistoric translocation events induced trophic
cascades with continental-scale impacts on fauna and flora” (Sullivan, Bird, Perry,
2017). The effect human existence has on multiple species is not only extensive
but visibly dramatic throughout history even prior to agricultural development.

            This review
also touches on arguably the most drastic effect humans have on other species,
extinction. Extinction as a consequence of human pressures is described as
having a cascading effect on evolutionary biology. This is partially due to the
fact that there is an ongoing mass extinction crisis “with 8–100 times higher
extinction rates over the past century for vertebrates than the long-term
background rate” (Sullivan, Bird, Perry, 2017). This is not to say that this
event is caused solely by human behavior, but it is certainly an immense contributing
factor and undoubtedly correlated to the current crisis. Human colonization in
vast parts of the world, along with climate change and other disputable factors
has shown to be an indirect contributor to the extinction of various species in
large islands and on a continental scale. To begin restoring damage inflicted
on other species and the ecosystem, an important aspect this review urges to
consider is the pre-history of human behavior in the natural environment and to
anticipate the future of anthropogenic impacts in order to mitigate their
intensity and recognize their long-term effects on the planet.

            As
a species, we view the world from a human perspective that places value and preserves
that which benefits us. However, in doing this we do not take into
consideration the well-being of other species and their necessities as much as
our own. Our needs are interconnected with those of all other species because
we coexist on the same planet. Therefore, it is important to make changes in human
behaviors as a species that will beneficially affect the environment we cohabit.
Due to humans’ powerful influence on evolutionary processes of other species,
the idea that there is a moral responsibility to conserve and restore the
ecological balance we’ve upset is one that we ar