BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: climate change (Page 2 of 2)

280 Million Year Old Trees in Antarctica

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On January 18, 2018

In Student Post

Geologists have discovered 280 million year old tree fossils, which could be evidence of the oldest polar forest in Antarctica. The scientists had previously found 260 million year old tree fossil fragments, and returned to find out how a forest could have flourished there.

Credit: Erik Gulbranson

Professor Gulbranson, one of the geologists on the expedition, believes the trees must have been an extremely hearty species to survive, and “The trees could turn their growing cycles on and off like a light switch. We know the winter shut off happened right away, but we don’t know how active they were during the summertime and if they could force themselves into dormancy while it was still light out.” The polar forest grew at a latitude (geographic coordinate– location) where plants can no longer grow today, and they grew in nearly half a year of darkness and five months of continuous light. They were able to grow in these conditions because they grew during the Permian Period, where Antarctica was much warmer than today and part of Gondwana (A supercontinent which was part of Pangea).

One of the biggest challenges for the team was dating the trees. The trees could be 20 million years older or younger than their dated age of 280 million years because of the margin of error. They are still researching why polar ecosystems changed during the mass extinction at the end of the Permian period, but their current theory is that 90% of all species were wiped out because of higher global temperatures and ocean acidification. Professor Gulbranson believes his work could help understand the effects of contemporary climate change.

For more information click here.

Avenging Lamarck: The Epigenetics of a Fish

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On April 5, 2017

In Student Post

The laughingstock of biology classrooms everywhere, the footnote to Charles Darwin and his widely acclaimed theory of natural selection, the scientist who has caused many a biology student to stop and wonder why he or she should even know his name, Jean Baptiste Lamarck has gotten a bad rap among student’s across the country. Predicting that evolution in species resulted from individual species adapting to their environment and morphing their bodies to better survive and reproduce, passing their adapted traits to their offspring, Lamarck has been criticized by students everywhere for simply not being correct. However, he wasn’t entirely wrong. Recent research conducted in the Gulf of St. Lawerence off the Labrador Peninsula has revealed that skate fish  in the area have developed differences in terms of size from other skate fish because individual organisms are able to turn on and off select genes.

https://en.wikipedia.org/wiki/Mottled_skate

The ability to turn on and off certain genes in organisms based on environmental conditions and pass those changes to offspring is called epigenetics. Epigenetics allows individual organisms to change their traits slightly to adapt to their environment. Where evolution by natural selection takes millions of years and results in the evolution of populations on a macro scale rather than individual organisms, epigenetic changes are much quicker.

Researchers were attracted to studying the winter skate fish in this bay because though the fish lies all along the North American coast, in this bay, the fish tends to be significantly smaller than other members of its species. Scientists attribute this to the warm water in this shallow water area which makes smaller organisms more likely to survive and reproduce.

However, DNA tests showed that significant changes in the genome of the fish weren’t what made them smaller, indicating it wasn’t Darwinian natural selection that dominated this process. The researchers discovered that the fish could turn on and off certain pieces of DNA in individual organisms to better adapt to the environment. Thus, the fish are able to adapt more quickly to changes in temperature than other organisms that rely solely on natural selection for changes to their traits.

Thus, Lamarck wasn’t entirely wrong all along (just mostly!).

The researchers hope this new information will help with conservation efforts and will give more insight into how species adapt to climate change.

So, do we owe Lamarck an apology? How can conservationists use this information to draw more interest to their goal?

Global Warming can alter the shape of the planet

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On October 15, 2015

In Student Post

Climate change is an element in our world which has been around for many years. It has been believed to cause warmer oceans and erratic weather, but a new study, according to scientists, declares it also has the potential to alter the shape of the planet we live in. Global Warming is a gradual increase in the overall temperature of the earth’s atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants. (read more about Global Warming) Michele Koppes,  assistant professor in the Department of Geography at the University of British Columbia, conducted a five year study in which she compared glaciers in Patagonia and in the Antarctic Peninsula. Koppes and her team discovered that glaciers in warmer Patagonia moved faster and caused more erosion than those in Antarctica, as warmer temperatures and melting ice helped lubricate the bed of the glaciers.

global warming

 Glaciers erode 100 to 1,000 times faster in Patagonia than they do in Antarctica.   “Antarctica is warming up, and as it moves to temperatures above 0 degrees Celsius, the glaciers are all going to start moving faster,” states Koppes. These ice sheets are apparently beginning  to move faster and should become more erosive. As a result, this will dig deeper valleys and shed more sediment into the oceans. The outcomes of this erosion add to the already complex effects of climate change in the polar regions.  “The polar continental margins in particular are hotspots of biodiversity, If you’re pumping out that much more sediment into the water, you’re changing the aquatic habitat,” Koppes states.  The Canadian Arctic, one of the most rapidly warming regions of the world, will most definitely feel these effects. These glaciers are on the verge of a major shift. The Canadian Arctic is becoming warmer in temperature more than four degrees Celsius spanning over the last 50 years. These glaciers will be flowing up to 100 times faster if the climate continues to shift and shifts above zero degrees Celsius. The findings by Koppes settle a scientific debate about when glaciers have the greatest impact on shaping landscapes and creating relief, suggesting that they do the most erosive work near the end of each cycle of glaciation, rather than at the peak of ice cover. If global warming continues to occur, change in formation of landscape due to higher water levels from melting glaciers is a strong possibility and may already be taking place. This will significantly affect all forms of life on earth.

 

Original Article:  http://www.sciencedaily.com/releases/2015/10/151001142222.htm

Citations:

http://www.whoi.edu/main/topic/global-warming

http://www.sciencedaily.com/releases/2015/10/151001142222.htm

 

Lightning Expected to Increase by 50 Percent with Global Warming

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On January 8, 2015

In Student Post

Thunderstorm_over_Corfu

University of California Berkley scientist David Romps and his colleagues analyzed 11 different climate studies and concluded that changing climate will include increased lightning strikes. The studies, focusing on cloud buoyancy and precipitation, showed an increased amount of water vapor due to warming air. Water vapor is the fuel for for thunderstorms and explosive deep convection in the atmosphere, and with increased amounts in the atmosphere the frequency and ferocity of these storms will increase. Precipitation-the total amount of water hitting the ground in the form of rain, snow, hail, sleet, etc.- is essentially a measure of how conductive the atmosphere is.  Buoyancy is measured in the form of CAPE, convective available potential energy. This measures how potentially explosive the atmosphere is. Romps found that by analyzing these two factors he could accurately predict strength, frequency, and size of storms.

Article Link: http://www.sciencedaily.com/releases/2014/11/141113142112.htm

Useful Links:

http://en.wikipedia.org/wiki/Thunderstorm

http://en.wikipedia.org/wiki/Convective_available_potential_energy

Image Link:

http://commons.wikimedia.org/wiki/File:Thunderstorm_over_Corfu.jpg

Why Climate Change shouldn’t Always be the Scapegoat

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On October 1, 2014

In Student Post

Seychelles,

A certain purplish-blue banded snail was rediscovered after initially deemed extinct by the general scientific community, stirring up the minds of the many who continue to debate the effects of climate change and what living things directly suffer its consequences. Firstly declared extinct by a highly regarded Seychelles mollusk expert, Dr. Justin Gerlach, the snail’s reclassification has caused backlash in the scientific community. With such a confident course of action in not only the declaration of extinction, but also the citing climate change as the primary reason, it is understandable and necessary that scientists should view this case with scrutiny and care. Gerlach attributed an insufficient amount of rainfall to the snail’s extinction, which he suggested was in direct association with climate change. Not alone, other scientists also backed his claims, agreeing that climate change caused immediate ramifications for this banded snail.

However, with the rediscovery of this snail, it is now essential not to overestimate the weight of climate change when discussing extinction and habitat loss, although we know climate change is a very real and growing concern. According to the UN’s panel on climate change there are more than a few other factors that can impact a species that can also sit in the shadow of climate change in inappropriate manners. It is irresponsible to use climate change as a scapegoat in certain situations, as it can prove to be detrimental in the future when in hindsight it may not have been the primary causation of a species decline. The UN panel provides us with data that reinforces the notion that mollusks suffer from extinction based on factors like pollution or invasive species. As Bjorm Lomberg suggests “climate change is a real problem, but the way it is increasingly blocking sensible thinking is depressing.”

As for the future, the rediscovery of this species can hopefully serve as an example of the disillusionment that can arise from a hyped phenomenon. Yes, climate change is one great problem, but it is one of many, and we must hold ourselves accountable to where our conclusions derive from. The only current certainty is that we have to do a better job at limiting these debilitating  factors.

Further Reading/Sources:

http://www.ctvnews.ca/sci-tech/seychelles-snail-believed-extinct-due-to-climate-change-found-alive-and-well-1.1996871

http://en.wikipedia.org/wiki/Aldabra_banded_snail

http://www.forbes.com/sites/paulrodgers/2014/09/20/extinct-snail-rediscovered/

http://news.mongabay.com/2007/0813-snail.html

http://islandbiodiversity.com/jg.htm

http://en.wikipedia.org/wiki/Bjørn_Lomborg

http://en.wikipedia.org/wiki/Seychelles

The Moral Roots of Trees

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On September 23, 2014

In Student Post

By Richard Sniezko

By Richard Sniezko

Recently in Southern Utah it has come to the attention of many ecologists that the tree species, whitebark pines, is on the cusp of becoming an endangered species due to climate changes and droughts in the south. As a quick solution, some members of the scientific community have suggested “assisted migration” whereas humans would restore the whitebark pine population by dispersing its seeds from areas of the hot south to more adaptable, cooler weather up north.

To put this proposition to the test, graduate student, Sierra McLane, under Dr. Sally Aitken of the University of British Columbia, conducted a study and spread the seeds of whitebark pines throughout much cooler and consistent weather of the British Columbian mountain ranges. As a result, 20% of the seeds germinated and continue to grow here, allowing McLane to affirm that whitebark pines would successfully grow in the colder climate.

Despite her evidence, McLane, along with many other scientists’ “assisted migration” is bound more by an ethical dilemma than biological. Although it is clear that these whitebark pines are a crucial species to provide animals, like bears and birds, with food and shelter, some scientists are skeptical over how easily these animals will be able to adapt to the change in their location and others are morally conflicted over whether humans should interfere with nature thus changing the future. While assisted migration continues be deliberated by scientists as a possible solution to the threatened whitebark pine tree population, what is your attitude on the subject? Do you believe it is our moral responsibility to “take care” of the environment or should we not interfere with the natural selection of wildlife?

Original article: http://www.nytimes.com/2014/09/23/science/under-theat-flight-may-be-best-response-for-trees.html?ref=science&_r=0

 

Deforestation is Out of Control

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On November 18, 2013

In Student Post

Deforestation has always been viewed as a problem by modern observers. No one can deny that the cutting down of forests is necessary for economic development and continued prosperity in some lumber rich nations, however, things are getting out of control. In a recent study, it was revealed that a total loss of 2.3 million acres of forest was destroyed in between 2000 and 2012. To put that amount in perspective, it is equivalent to six Californians or the entirety of the United States east of the Mississippi River. This massive loss of forest land was countered by a gain of only .8 million acres, resulting in a 1.5 million acre net loss of forest land around the globe.

According to Ritchie King, a reporter on the subject, “Deforestation at this scale is having a tremendous ecological impact, on both species and climate. From 2000 to 2011, deforestation effectively added 14.5 billion tonnes (16 billion tons) of carbon to the atmosphere, about 13% of the world’s total contribution to climate change.”  Some nations who, in the past, have been the greatest culprits of deforestation, such as Brazil, have cut back their logging and have greatly reduced the rate at which land is cleared, however, in other parts of the world, particularly Indonesia, (if you scroll to the bottom of the article there is a graphic) deforestation has sped up rapidly. Not only does deforestation threaten the world as a whole through the production of a large precent of the earths greenhouse gases, but it also threatens the delicate forest ecosystems around the world. Heavy deforestation in areas with Rain forests, such as Brazil and Indonesia threatens the unique species of plants and animals which live there, and threatens to reduce the biodiversity present on Earth.

Deforestation in Brazil

Colorless Coral?

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On September 25, 2013

In Student Post

Screen shot 2013-09-24 at 9.51.23 PM

 wildsingapore.com on flickr

When one usually thinks of a coral reef they think of bright vibrant colors… this may not be the case anymore. A recent study has found that climate change may be depleting coral of its color. In a process called “bleaching” the color is removed from the coral when the symbiotic algae that provide nutrients to the coral either lose their  photosynthetic pigmentation and their ability to perform photosynthesis or disappear entirely from the coral’s tissue.

While this strange and disturbing phenomenon has been receiving a lot of attention, there is very little concrete knowledge about the exact molecular process that causes the bleaching. Many hypothesized that the bleaching is a result chloroplast damage due to heat stress, which results in the production of toxic, highly reactive oxygen molecules during photosynthesis, they are linking the origin of the heat stress back to climate change.

To test this theory a team of researchers from Carnegie led by Arthur Grossman and accompanied by a few other scientist from Stanford conducted a study that resulted in the surprising discovery that the bleaching occurs when the algae is not performing photosynthesis, while it is surprising the team also concluded that it could be beneficial to aid in the fight against coral decline. “This is surprising since it means that toxic oxygen molecules formed in heat-damaged chloroplasts during photosynthetic reactions during the light are likely not the major culprits that cause bleaching.” (biologynews.net)

While their initially theory was incorrect, this research has now motivated further study into the  molecular functions of coral as well as further efforts toward coral preservation.

 

http://www.biologynews.net/archives/2013/09/05/clues_in_coral_bleaching_mystery.html

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