11/24/2016

In Indigenous Genes, Evidence of Colonization’s Plagues

11:50 minutes

In the years after Europeans arrived in the Americas, indigenous communities were ravaged by disease that the colonists brought with them, from influenza to smallpox. New genetic research published in Nature Communications now describes one way that the course of history may have changed the genetics of Coast Tsimshian communities in northwestern British Columbia.

A genetic comparison of ancient Tsimshian remains and modern Tsimshian community members found shifts in a part of the genome responsible for regulating immune function. Some variants found in the ancient remains were rare in the living, suggesting they were less helpful for surviving the European pathogens.

Ripan Malhi, an anthropologist at the University of Illinois at Urbana-Champaign, headed the project. He says the research also confirms a well-known piece of history: The arrival of European diseases meant the deaths of a huge proportion of the community—over half, according to the model used by Mahli’s team.

The Metlakatla First Nation was one of the two Tsimshian communities participating in the research. Barbara Petzelt, treaty coordinator for the Metlakatla Treaty Office and a co-author on the study, explains the value of having scientific data that matches up with the nation’s oral histories. Petzelt and Malhi also discuss the unique collaboration between the research team and the Tsimshian communities, and why they think building relationships with indigenous communities makes for better research into genetics, and beyond.

Segment Guests

Ripan Malhi

Ripan Malhi is an associate professor of anthropology and genetic anthropologist at the University of Illinois at Urbana-Champaign in Urbana-Champaign, Illinois.

Barbara Petzelt

Barbara Petzelt is an archaeologist and the treaty coordinator at the Metlakatla Treaty Office in Prince Rupert, British Columbia.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. If you celebrated Thanksgiving yesterday, I hope it was a good one spent with family, eating good food, reflecting on what you’re thankful for. And given the holiday’s historical roots, it’s also a good time to reflect on how indigenous Americans fared after colonization and wars, forced relocation, and disease all took their toll. And the legacy of colonization is still felt by Native Americans today, even it turns out in their DNA.

New research published in Nature Communications assesses the impact of European colonization on the genes of one indigenous group of British Columbia, finding in their DNA evidence of devastation from disease, smallpox included, in the 19th century. The researchers compared samples from ancient remains of people in the Prince Rupert’s island area to living members of the Tsimshian first nation. And they found changes in their immune systems and evidence of a huge loss of life about 200 years ago.

The lead author on that research is Dr. Ripan Malhi. He’s a genetic anthropologist, an associate professor at the University of Illinois at Urbana-Champaign. He joins us from Tampa, Florida.

Also with us is Barbara Petzold. She is treaty coordinator at the Metlakatla treaty office. She’s an archaeologist and part of the research team. And she joins us from Metlakatla in British Columbia, Canada. Welcome to Science Friday.

RIPAN MALHI: Hi, great to be here.

BARBARA PETZOLD: Thanks for having me.

IRA FLATOW: The Metlakatla are a first nation within the Tsimshian. Is that correct, Barbara?

BARBARA PETZOLD: Yes. They’re one of seven of the Tsimshian’s first nations.

IRA FLATOW: And Dr. Malhi, how different were the genes you looked at between the ancient and modern groups of Tsimshians?

RIPAN MALHI: Well, for the whole genome or the genome wide scan that we did, the ancient individuals and the living individuals were very similar so much so that we could suspect that there are a continuous population. But for specific genomic regions, we’ve found signals of natural selection in the ancient individuals specifically add genes related to immunity. And so this suggests that the ancient individuals were actually adapted to any pathogens in their ancient environments.

IRA FLATOW: And how did they lose that immunity then?

RIPAN MALHI: Well, it seems that after European contact that other pathogens were brought over from Europe. And one possibility is that these ancient genetic variants that were well-adapted to ancient pathogens were no longer adapted to the current pathogens that Europeans brought over. And so these genetic variants changed dramatically as a result of that in the living community members.

IRA FLATOW: Barbara, how much of this research is new information to you?

BARBARA PETZOLD: Well, considering a lot of this information was passed down in our oral histories and through the archaeological record, not much of it’s actually surprising. The interesting part is that it’s actually shown in our genetics. So that part is a little surprising and pretty exciting.

IRA FLATOW: Tell me why. What’s so exciting about it?

BARBARA PETZOLD: Well, science is catching up to be able to show that the genetic shift in one population from ancient descendants into the modern descendants. In a previous study, we’ve already– we meaning the geneticists– have already proven that there is a genetic link between the ancient ancestors, the ancient remains from the sites within the territory and with the modern descendants. And to go the step further to show that, yet smallpox epidemic, for example, that occurred within the region at the time of contact and just after in the early start period actually shows up in our genetics is pretty interesting, from what I understand, quite ground breaking.

IRA FLATOW: And, Dr. Malhi, how do you think the Tsimshian can use this data? Does anything also excite you about these findings?

RIPAN MALHI: Oh, yes. I think the results that we found were really exciting in part because this is, at least, in the Americas the first time that we’ve been able to show through study of genetics of a continuous population before and after European contact what the effects of European colonization was. The other part of this that I think is really interesting is the partnership that we have with the Metlakatla and the [INAUDIBLE]. So it was a study where we both decided what we wanted to study and how we wanted to study it.

IRA FLATOW: So are you saying this is a unique partnership that hasn’t happened before?

RIPAN MALHI: It rarely happens in anthropology and genetics, a partnership between a team of researchers at an academic university and indigenous communities. What’s happened a lot in the past is that researchers would go into a community, get the samples that they needed, and then they would leave, rarely coming back to report any results. And so we don’t want to follow that model.

And so what we did is met what the communities, decided what would be a mutually beneficial study. And then we would come back year-after-year to report on our results and discuss the results with community members and folks like Barbara and [INAUDIBLE] Mitchell, our community collaborators.

IRA FLATOW: Barbara, so you in the community welcomed this then?

BARBARA PETZOLD: Like Riphan said there were things that we wanted to get out of it as well, you know, like proving the genetic link between Metlakatla modern descendants and the ancient ancestors from sites within a territory and also aid in the advancement of science, which also helps with the yearly results reporting. We think it might actually inspire some of the younger members to go into sciences.

IRA FLATOW: You mean the youngsters who are part of this study might say, hey, you know, there’s a door open to science that I never thought I might walk into?

BARBARA PETZOLD: That’s a hope. We’ve had a focus before on archeology. And some of the members have started showing an interest in becoming field assistants and hopefully, will further their education in that. And with the genetics research, we’re hoping too that maybe some of the members might be inspired to go into sciences.

IRA FLATOW: Mhm. Dr. Malhi, does collaborating with indigenous communities ever lead to changes in your research questions or your methods?

RIPAN MALHI: Oh, absolutely. Yes. So we discuss our methods that we are planning to use. And often, through this type of discussion, we end up changing our research methods. A good example would be not with the Metlakatla, but with another community that we were working with in Alaska.

We were planning on using hair for a certain type of analysis, until we found out from the community that hair is sacred. And so we should not do that. And so we quickly changed the way we were going to approach the study to not use hair, since it was sacred for community members.

IRA FLATOW: So you had collaboration with the community members beforehand about their feelings about this research and where your limits should be?

RIPAN MALHI: Right. So it seems to be a continual discussion year-after-year. So we’ll start off with what we want to pursue in mutually beneficial research project. And then that may evolve as we go back and learn about the results and other things change. And so it changes throughout the lifetime of the partnership.

IRA FLATOW: Now you feel the same way, Barbara?

BARBARA PETZOLD: Yes. Yeah. It’s actually been a pretty interesting relationship that we have with Ripan and his team. It makes us feel that we’re not just subjects of research and that we’re actually a part of it and helping to drive it.

IRA FLATOW: Were you ever fearful that once the scientist came in and were doing genetic research about the history of your nation that they might reveal histories or other aspects of your community that you did not ask them to go look at? I’m specifically thinking of other histories before, where scientists have come in and done genetic research and were at odds about the history of the nation, where it came from, which they did not want the scientists to explore.

BARBARA PETZOLD: It’s pretty well-known to the members that this is their territory. And we didn’t expect the results to be any different, and they weren’t. They actually corroborated what we’ve been– what the community has been saying all along.

We were more concerned about the relationship, because there’s nothing more personal than your DNA. And we had spent quite a bit of time with Ripan talking about the proposed research, looking at various informed consents from different organizations and from the University of Illinois and looking at the ethics of using genetics for research and came to an understanding and were able to explain the science to the members. And with the informed consent, we’re pretty comfortable and having the research go forward, because we both wanted something out of the relationship.

IRA FLATOW: Dr. Malhi, what other research projects are you working with Native American communities on?

RIPAN MALHI: Well, right now I have a few projects going on in British Columbia, California, and Alaska, but I’m most involved in the Alaska project right now with Alaska natives, where we are actually looking at epigenetics or how the environments can change or mark your genome and the expression of genes. And we’re looking at the epigenetics of European contact and colonization to see how this dramatic change in the environment and social lives of indigenous peoples in Alaska may have been affected by European conduct colonization.

IRA FLATOW: And, Barbara, does this experience affect any of your treaty negotiations going on now?

BARBARA PETZOLD: Well, not directly and without being seen what her positions are. But every time that we have the ability to back up our oral histories using other methods, scientific, archaeological, what have you, is always beneficial to us.

IRA FLATOW: That’s great. I want to thank you both for taking time to be with us today.

RIPAN MALHI: Great. Thank you.

BARBARA PETZOLD: Thanks.

IRA FLATOW: You’re welcome. Dr. Ripan Malhi is an associate professor of anthropology, University of Illinois in Urbana-Champaign. Barbara Petzold is treaty coordinator at the Metlakatla Catholic treaty office.

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