Evolution is a continuous and ongoing process
that has shaped life on Earth, as far back as life on Earth has existed. And like history, this process hasn’t somehow
stopped just because we’re now here to experience it. The problem with the theory of evolution,
however, is the fact that we can’t directly see it in action, since it’s not something
that happens all of a sudden, but as a slow and gradual process, taking place over many
generations. As a sort of embodiment of the law of cause
and effect, evolution works by giving living organisms the edge needed to survive and even
thrive in different environmental conditions. So the faster the changes in the surrounding
habitat, the faster life needs to adapt in order to keep up with these variations. And today’s world is nothing if not “fast-changing.” So, in order to prove this theory once and
for all, here are some direct and observable examples of rapid evolution at play. 10. Weeds Change In urban environments, where most of the ground
is covered in asphalt and concrete, plants have to make due with whatever patches of
exposed soil they can find. And in some cities this available soil makes
up just 1% of the entire surface area. So, given the short supply of viable real
estate, some plants have begun to change their ways in terms of how they spread their seed. This is something that Pierre-Olivier Cheptou,
the research director at the Centre d’Ecologie Fonctionnelle et Evolutive (CNRS) in Montpellier,
France, has observed with a daisy-like weed growing in the city. These plants make use of two kinds of seeds
– one that’s heavier and falls straight to the ground, and another, lighter type that’s
usually blown by the wind in different locations. As compared to the same species growing in
rural areas, the urban variant growing in Montpellier has begun favoring the heavier
seeds, instead of the wind-blown ones. What’s more, Cheptou concluded that this
process only took 12 years to happen. The reason for this change is the higher chance
of reproduction if the seeds fall on the same patch of soil, close to the parent plant,
rather than if it’s blown by the wind to a parking lot somewhere. But if this trend continues and the urban
plant ends up renouncing its lighter seeds altogether, it may be susceptible to another
danger. “The downside is that the population fragment
is vulnerable if the environment changes there; it will not be able, ever, to reach new and
fertile ground if it gives up the potential for long-distance dispersal,” said Martin
Cody, a plant biologist from the University of California. 9. Differently-colored Owls Tawny owls are commonly found in woodlands
all across Eurasia and come in two main colors – grey and brown – depending mostly on
their environment. Their plumage color doesn’t change throughout
their lifetime, and when two differently-colored tawny owls mate, the grey gene is dominant
– meaning that their offspring will mostly be of that color. Grey owls also have a slower metabolism and
a stronger immune system, giving them an overall advantage over their brown counterparts. But their population is shrinking nonetheless. Over the past three decades, the number of
brown owls living in Finland has increased from 30 to 50 percent. And given the previously mentioned disadvantages
brown owls have, this doesn’t seem to make sense. But because winters aren’t as long or as
severe as they once were, being brown in Finland no longer sounds like a bad idea – especially
when it comes to owls. Plumage color helps these birds hide from
both predator and prey alike, by allowing them to blend in with the surrounding environment. And since a snow-covered landscape isn’t
as common, being grey puts the owl at a serious disadvantage. Their plumage literally makes them stand out,
meaning that they’re now an easy-to-spot target. If this trend continues, then the grey owl’s
days are numbered. 8. Tuskless Elephants Since we’ve proven ourselves to be quite
ineffective when it comes to protecting elephants from poaching, evolution has stepped in to
get the job done for us. And the way it went about it was to make the
elephants be born with smaller or no tusks whatsoever. Under normal circumstances, tuskless elephants
represent about 2 to 4 percent of the total population – with females being predominant
in that group. But in a 2008 paper published in the African
Journal of Ecology, it was revealed that the number of tuskless females in Zambia’s South
Luangwa National Park had risen from 10.5% in 1969, to 38.2% in 1989. In a similar report, the number of tuskless
elephants in Uganda was between 9-to-25% of the entire population, depending on the region. This trend was visible in every elephant population
that went through a wave of heavy poaching. As more and more tusk-sporting elephants are
being killed, the tuskless will become predominant in the group. If this happens, the elephant will hopefully
be spared from future slaughter. But this sacrifice, even if it translates
to their survival as a species, has its own series of disadvantages. Elephants use their tusks in a wide variety
of ways, like digging for food and water, carrying logs and branches around, or for
protecting themselves from predators. Experts say an elephant without tusks is a
crippled elephant, given that it can no longer make use of them. They can still survive, given the circumstances,
but they’ll have a harder time doing it. It would be like humans being born without
fingers, for example. 7. New York’s Bedbugs are Tough SOBs Bedbugs seem like the sort of problem that
we’ve dealt with already. And this is somewhat true, given the fact
that bedbugs were almost wiped out from North America roughly 60 years ago, thanks in large
part to DDT – an insecticide that’s since been banned for its devastating health and
environmental effects. But in more recent years, bedbugs have returned
with a vengeance, tormenting thousands of sleepers across the country – with New York
being declared as America’s most bedbug-infested city. So, what happened? Well, as it turns out, the phrase “what
doesn’t kill you, only makes you stronger” is more than true in this case, since some
of these little critters have evolved to be 250 times more resistant to insecticides than
their 1950s ancestors. These mutations happened randomly within the
bedbug population, all across the country, with countless of them dying before several
got exactly the right kind of genetic variation needed to withstand those insecticides. And once they did, much of the population
quickly adopted the mutation, thanks in large part to the fact those who didn’t have it
were still being killed off. Today, even the strongest of insecticides
barely make a dent in the bedbug populations that have this genetic variation, and have
begun to spread through the US once again. The pace at which this insecticide-resistant
mutation has spread indicates that relying solely on chemicals is no longer a viable
option. Sleep tight! The same thing can be said about various bacterial
infections. Since we’ve begun using antibiotics at an
unprecedented rate in recent decades, certain strains of bacteria have become resistant
or even immune to our only defense against them. 6. Predators and Superpredators We tend to think of mountain lions as apex
predators, sitting comfortably at the top of the food chain in their native habitat. We see them as powerful creatures, stalking
their prey from the shadows and pouncing when we least expect them. But while this was somewhat true, these cougars
have since learned the hard way that their position as ‘top dog’ has been taken over
by another, even greater predator – humans. Being hunted for hundreds, if not thousands
of years, pumas have developed a healthy fear of humans. In a study performed on mountain lions in
California, it was revealed that these powerful creatures run away at the mere sound of human
voices heard in the distance. They do so even if they’re feasting on a
kill. Researchers placed motion-sensor cameras and
audio devices around a recent kill, and waited for these pumas to come back to them. When they did, the devices turned on and the
cougars started running away for dear life. Various radio talk show segments were used
for these experiments, where the hosts weren’t yelling or being agitated – using instead
the most benign discussions the researchers could find. They also used frog noises half the time in
the audio recordings, in order to keep the study consistent. The results showed that the pumas had no reaction
while the frog sounds were playing. But when human voices were heard, their response
was almost instantaneous – freezing in place and then immediately running away. In several cases, the cougars were so frightened
that they completely abandoned their kill –not returning even after several days. We can easily call this a case of behavioral
evolution. Now, whether this fear of humans is something
that’s already been implanted into their genes or it’s something they’re taught
from a young age, we still don’t know. Nevertheless, it’s important to remember
that a mountain lion is more afraid of you than you are of it. But you still probably shouldn’t try to
ride one, Karl. 5. ‘Plenty’ of Smaller Fish in the Sea Overfishing is a serious problem the world
is facing right now. If things will remain the same, statistics
show that by 2048, the world’s oceans will be completely devoid of any commercially-viable
fish. When will we learn that we should never have
taught a man to fish? Anyway, some measures were put in place in
order to safeguard this global food supply. For several decades now, these regulations
stated that only fish above a minimum size can be captured, while smaller fish should
be allowed to reproduce at least once or twice. And in theory, these laws ensured that the
global fisheries won’t disappear, while fishermen could focus only on larger, high-value
fish. A win-win situation, as some may say. But in the 1980s, a worrying report came out,
describing a phenomenon not anticipated by the people who passed these well-intentioned
laws in the first place. Not only are the global fisheries collapsing,
but the fish that still exist are smaller than they once were. First, larger fish produce more eggs and end
up having more offspring as a result. When these fish are removed, the overall population
will have a harder time of replenishing itself. Second, it was revealed that this decades-long,
size-selective fishing has actually caused fish to reach sexual maturity at a younger
age than under normal circumstances. This means that some populations of heavily-fished
adult fish today are 50 to even 60 percent smaller in size and weight than they were
back in the ’70s. And as the bigger ones are being captured
while the smaller ones make it through the nets, this trend will continue. This phenomenon is also greatly exacerbated
by climate change. Since warmer water holds less oxygen, fish
also have to shrink in order to accommodate to their changing environment. 4. Moscow’s Strays A truly fascinating phenomenon is taking place
on, and under, the streets of Moscow. Today, the city is home to roughly 35,000
stray dogs, which is about one for every 300 human inhabitants. That’s a lot, and a situation that stems
back to at least the mid-19th century, when various Russian writers began mentioning it
in their works. Andrei Poyarkov, a researcher at the A.N. Severtsov Institute of Ecology and Evolution,
has been studying these strays for some time now, and has come to some really interesting
realizations. These dogs are rapidly evolving to better
adapt to their urban environment. Poyarkov observed that, over time, these strays
tend to lose their spotted coats, wagging tails, and the overall friendliness that separates
them from wolves. They’ve also developed a series of traits
optimized to fill four distinct niches that allow them to thrive. Poyarkov labeled them as guard dogs, scavengers,
wild dogs, and beggars. The so-called guard dogs serve as semi-feral
assistants to security personnel all over Moscow’s many fenced-in locations. The security guards are seen by these dogs
as their masters, who feed them in return for their services. The scavenger ‘class’ is made out of dogs
who roam the city’s many garbage sites. The wild dogs are the most feral, and rely
predominantly on hunting mice, rats, birds, cats, and other small animals they can find. Lastly, we have the beggars, which are probably
the most interesting. Not only have these dogs developed the ability
to better recognize people who are the most likely to give them food, but have also mastered
the ability to travel by subway and recognize distinct stations that are part of their territory. Additionally, Poyarkov says that, since these
beggar dogs rely more on brains than brawns for their survival, the alpha male position
in the pack is taken by the smartest, and not necessarily the strongest dog. 3. Religion vs. Evolution No, we’ll not be getting into that particular
debate, so don’t worry. We will, however, be focusing on how religion
has influenced a certain species of fish to rapidly evolve or disappear. Every year, a religious ceremony took place
in a cave in Mexico where the locals poisoned the water with a natural toxin extracted from
various plants. The fish that live in this cave, the Poecilia
Mexicana, or more commonly known as the Atlantic molly, were being paralyzed by the toxin and
began floating to the surface, where the locals collected them for the community. This is a tradition that’s been passed down
through the generations, and where these fish were regarded as gifts from the gods of the
underworld. A group of researchers has analyzed these
fish and compared them to others of their species, but from elsewhere in the region. And as it turns out, the cave fish are 50
times more resistant than the other Atlantic mollys. Now, even though most still eventually die
from the toxin, they’ve adapted to such a degree that many are able to survive the
religious ceremony and pass down their genes to the next generation. The government has banned this particular
tradition in recent years, hoping to conserve the species, but evolution may have beaten
them to the punch. 2. For When the Family Moves In The Carolina anole, or more commonly known
as the green anole, is a species of lizard native to the southeastern United States,
as well as several Caribbean islands, close to Florida. This lizard also has a cousin, the brown anole,
common in Cuba and the Bahamas. Back in the 1950s, some of these brown anoles
hitched a ride on agricultural shipments from Cuba and made their way to southern Florida,
among other places in the US. Nevertheless, it was in Florida where they
met their long-lost cousins and had a good, old-fashioned family reunion. But as these reunions sometimes go, these
new arrivals overstayed their welcome. In fact, the green anoles had to go as far
as move and leave the newcomers in their old home. A short while after contact, the native species
of anole was, more or less, forced to move higher-up in the branches of trees. And what’s particularly interesting here
is that the green anole went through a series of changes that made them better suited for
their new lifestyle. In just 15 years and roughly 20 generations,
their toe pads had become larger, with more sticky scales on their feet. These adaptations are preferred when it comes
to the thinner and smother branches found higher up in trees. “To put this shift in perspective, if human
height were evolving as fast as these lizards’ toes, the height of an average American man
would increase from about 5 foot 9 inches today to about 6 foot 4 inches within 20 generations
an increase that would make the average U.S. male the height of an NBA shooting guard,”
said Yoel Stuart, a postdoctoral researcher at the University of Texas. 1. Plastic-eating Bacteria Besides the law of cause and effect, evolution
also seems to follow the law of supply and demand. Because, in another example of rapid evolution,
certain bacteria have developed the ability to break down and consume PET, the most common
plastic found in clothing fabrics, food and drinks containers, landfills, and, of course,
the ocean. This plastic’s appeal was that it’s lightweight,
colorless, flexible and strong, and it can be used in a wide variety of ways. But it’s also notoriously hard to break
down by microbes in a process we know as biodegradation. Nevertheless, a team of Japanese researchers
has recently identified a species of bacteria, the Ideonella sakaiensis, which is able to
do just that – break down PET and use it as energy. What’s more, they’ve noticed that this
bacterium only uses two enzymes to get the job done. This is a fascinating discovery, given the
fact that these plastics have only been around since the 1940s, and have become predominant
in the environment only in more recent decades. This discovery truly pays homage to the versatility
of life and the evolution that enables it. We shouldn’t, however, let ourselves be
fooled into thinking that these tiny creatures will be able to clean up our mess, because
they can’t. The time it takes them to break down this
plastic is too long to be put to any practical use at the moment. Scientists have observed that it needs up
to six weeks and a steady temperature of 86 degrees Fahrenheit to consume a thumbnail-sized
piece of plastic. Still, knowing the process through which plastic
is broken down, scientists are thinking of transferring those particular genes to a faster-growing
bacterium that can get the job done in a shorter period
of time.
