Wednesday, November 26, 2014

Ten Stories to Be Thankful for This Thanksgiving

1. In Western Australia, a species once thought to be locally extinct (extinct in that area only-not globally), was spotted again after a decade long absence. Highly sensitive to habaitat disturbances, it seems like the spectacled hare-wallaby has managed to prevail.

2. Climate change and the need to be green are topics familiar to most people in western countries, but greening up practices is harder in areas where hunger and access to basic sanitation are real problems. That hasn't stopped Ethiopia from deciding to transform sewage to fertilizer and biogas. Talk about an interesting source of renewable energy.

Wind energy is more affordable than ever
3. Solar and wind power have been out of reach for most due to their high costs.  Prices are changing though and wind and solar power are more affordable than ever, with prices down 50-70% in recent years. While not yet a replacement for goal and natural gas, I'm thankful we're getting closer.

4. I'm proud to be an American after the U.S. pledged 3 billion dollars to the Green Climate Fund. The U.S.'s pledge puts us significantly closer to the goal of 10-15 billion raised (we're just under 7 right now). The GCF redistributes money from developed countries to less developed countries and helps them tackle climate change.

5. You've probably heard about the Galapagos Islands, a series of Islands with high biodiversity. Well, giant tortoises were once very near extinction on these islands, but they're making a comeback! Only 15 were left in the 60s but now there are over 1,000!

6. The second most populated country in the world, India, recently announced it will invest 1 billion dollars to renewable energy. They're looking to double their wind energy capacity by 2019. Way to step it up India.

7.  In what is one of the most exciting stories of an "extinct" species coming back from the dead I've read in a while, it looks like there's at least one Sumatran rhino left in the wild. Whether or not enough Sumatrans rhinos exist to maintain a sustainable population is uncertain and perhaps unlikely, but there might be some hope left, and that's good news.
Air pollution

8. Obama is expected to announce even stricter regulations on ozone emissions sometime today. I'm thankful we'll see less smog from factories and power plants. Everyone deserves clean air to breathe.

9.  Arizona residents have a new neighbor, not seen in decades, the gray wolf is back. A female wolf has been spotted wandering around the state. Let's hope a male decides to join her.

10. Finally, China and U.S. made the headlines globally when they reached a climate deal. China agreed to slow and curb carbon emissions. This historic deal means China will reach peak emissions by 2030 and then curb them, putting an actual deadline out there for the first time. This something we all should be thankful for.

Thanks for reading and Happy Thanksgiving! There's a lot of work to be done but there's a lot to be thankful for too!

Monday, November 17, 2014

Mean male chimps produce more offspring-implications for humans?

A study came out about chimpanzees recently that has received a lot of attention. You may have seen a headline on sites such as ScienceDaily, Smithsonian, and other websites stating that male chimps that bully females are more likely to reproduce. Specifically, researchers looked at 16 years worth of data from Gombe National Park in Tanzania (Gombe is where Jane Goodall first studied chimps). They found that males that were sexually coercive, or those or threatened or used force against females,  fathered more young than males that were less violent towards females. Male chimpanzees that acted violently towards females year-round (as opposed to just when females were receptive, or ready to mate,) were more successful. Those males that increased aggressive behavior towards females only when females were receptive did not have any advantage in fathering offspring.

Our closest genetic relative, the chimpanzee
Now, this study is a great example of how results and interpretations differ. It also presents the perfect opportunity to talk about how science reporters for the general public often misunderstand or sensationalize scientific research. News sites will get more people to click on their site if they use certain words and only report some facts to create a more interesting (although probably misleading) story.

The fact is, there are many ways to interpret this study, and the close genetic relationship between chimpanzees and humans means that of course we're all going to ask, what does this mean for humans?

Well, with sixteen years of data, there's certainly enough evidence to say that bullying females provides an advantage for chimpanzees at Gombe. However, how do we not know that these bullying males are aggressive with all chimpanzees, males and females and that aggression in general is the trait increasing their sexual advantage? Maybe this is the case or maybe not. My point here is simply that chimpanzees and complex and their reproduction and mating rituals are also complex.

Chimpanzee and offspring Photo credit: Neil McIntosh
It's not as simple as saying, "Oh, well if chimps that are mean towards females are more successful reproductively, the same must be true for humans." Many factors go into chimpanzee reproduction and many factors go into human reproduction. As similar as we are, we are not the same. Study author Joseph Feldman even states on ScienceDaily, "The glaring difference between chimpanzee and human mating behavior is that in chimpanzees females mate promiscuously with most male group mates during most cycles, while human females do not. Thus, the system that favors male coercion in chimpanzees is not present in humans to favor this behavior." The authors also point out a fact that all of the articles I've read so far seem to overlook: studies of chimpanzees at other sites have not found a link between sexually coercive males and the number of offspring they father. Thus, we need to remember that these results are specific to the chimpanzees studied at this site and not all chimpanzees in Africa.

The take home messages are; 1) be careful when reading about science from sources other than the original scientists and 2) with animals and biology especially, remember that simple studies are needed for us to ask answerable questions, but that the reality may be very complex.

Thursday, November 13, 2014

What is an ecological niche?

What is an ecological niche? This is a question you'll probably encounter if you study primatology/ecology/zoology/etc. If I search for "niche" in the dictionary that comes with my Mac, I find that niche is "a position or role taken by a kind of organism within its community."  But what does that mean? Niche is a concept I found some students in the introduction to anthropology course struggled with, so let's take a closer look.
Some factors that contribute to niche

A niche is more than just the environment an organism lives in, it really is the role the organism takes (so the dictionary definition isn't entirely bad). It's not just where an animal lives, but the animal's behavior, what time of day its active in its environment, what foods it prefers most to eat, what foods it can eat when preferred foods aren't available, and so forth. How an animal responds to resources is part of its niche as is how it may respond to any predators. An animal's life history, or the sequence of events from birth to death related to reproduction, is also part of its niche. Many animals occupy the same environment. You could sit very, very quietly in a tropical forest for a couple of hours and see multiple animals exploiting a single fruiting tree.

If we just talk about primates for a minute, we may find one species of primate eats leaves from this tree. A second primate species consumes the ripe fruit on the tree during the day. A third species of primate ignores the fruit entirely, is only active at night, and instead hunts for insects and small reptiles on this tree.

Fundamental vs realized niche
This is an over simplified example though because a niche really is more than just diet or just habitat. Niches are complex. The actual or realized niche of a species may very well be entirely different from its fundamental niche, or the entire role/area a species could utilize in its niche if free from limitations. For example, while a primate that lives mainly on leaves may love to eat fruit, other competitors may prevent that primate from doing so. Thus, the realized niche does not include fruit but the fundamental niche does, because the primate is capable of foraging and feeding on that fruit. Keeping in mind the difference between realized and fundamental niche, different populations of the same species may have different realized niches. Let's say there are two populations of the same primate species but they live in slightly different patches of forest. Depending on the predators and conditions in each of those two forests, the same species may be able to exploit resources differently or have slightly different behavioral patterns because of lower predation rates in one forest compared to the other. Thus, the realized niches might differ.

Food for thought: I'd say humans have one of the most flexible and largest ecological niches of all species. Would you agree?

Here's a cool article about the first visualization of an ecological niche. Check it out!

Monday, November 3, 2014

Connections between Ebola, primates, and the bush meat trade

You may or may not have heard by now that many outbreaks of the deadly Ebola virus originated when people handled or ate animals infected with the virus. For those who need a refresher, a virus is an infective agent that is only able to multiply inside a host's living cells; a virus may cause an infection or disease. Fruit bats, primates, porcupines, and other animals can all carry the Ebola virus. It is only when a person touches or ingests the infected animal's bodily fluids (blood, sweat, mucus, etc) that a person risks infection. So, if you pet a chimpanzee on the head, which you're not crazy enough to do, you wouldn't risk getting sick, even if that chimpanzee was infected with Ebola (unless that chimpanzee had a very sweaty head). If you ate that chimpanzee for dinner though, you would risk contracting Ebola.

You may prefer a steak from a cow, but not everyone does
Photo credit: public domain

And there lies the connection between primates, Ebola, and the bush meat trade. Bush meat, or meat from animals that are not domesticated (bred or trained to need and accept the aid of humans), can be a primary source of protein for those living in Africa. Animals may be hunted by individuals simply to feed their own family, or animals may be hunted for commercial profit. More and more urban areas are consuming bush meat though, and in some instances this meat is even seen as a prized delicacy, a symbol of status and wealth.

As you've probably realized by this point, the bush meat trade can cause several problems. For starters, people may consume animals that are endangered or threatened, lowering their already low numbers. In Africa, the bushmeat trade is the most significant immediate threat to wildlife. While hunting primates and other wildlife to feed your family may or may not be sustainable depending on how the quantity and frequency of hunting, the abundance of the hunted animal, and other variables, the commercial bush meat trade is definitely not sustainable. Infant primates or other young offspring will die if their mother is hunted, leading to more loss. Concerning today's topic though, consuming bush meat leads to the transfer of disease from animals to humans. Thus, the bush meat trade is not only bad for the wildlife in the dinner pot but it's also sometimes quite bad for the humans eating out of the pot.

Bush meat in Ghana
 While the Ebola virus is thought to have originated in fruit bats, primates and other animals can carry it as well. Primates are especially a problem because we're so closely related to them. It's very easy for us to contract diseases from primates compared to animals we're not as closely related to. You may have heard that we share 98% of our DNA with chimpanzees, for example. Well, this close genetic relationship means that many of the diseases we can contract can be contracted by non-human primates too and vice versa. Hepatitis and herpes B can be transmitted from animal to humans, HIV originated in chimpanzees as SIV, and tuberculosis or TB can easily be transmitted from humans to non-human primates.

So in areas where bushmeat is the only source of animal protein available, you may purchase some meat at the local market, take it home and serve it up to your family for a filling dinner, and have unknowingly served an animal that was sick and infected with Ebola. While at first it may seem easy to place the blame on those consuming bushmeat, remember that many have consumed bush meat before without getting sick and may not realize that this is how the disease is transmitted. Those selling bush meat depend on this income to support their families. If people are educated on how Ebola is contacted and how unsafe bush meat is, the demand for it will hopefully decrease, preventing future outbreaks. Providing safe sources of animal protein may be another step towards decreasing the demand for bush meat.

Food for thought: How does this post connect with cultural relativism?