africa | OpenSTEM Pty Ltd

What Makes Humans Different From Most Other Mammals?

Well, there are several things that makes us different from other mammals – although perhaps fewer than one might think. We are not unique in using tools, in fact we discover more animals that use tools all the time – even fish! We pride ourselves on being a “moral animal”, however fairness, reciprocity, empathy and cooperation have been demonstrated in apes and monkeys. Genetically we differ by only 1.09% from gorillas, 1.14% from chimpanzees, 2.46% from Old World monkeys and we share 50% of our DNA with bananas!

Recent research has demonstrated one of the ways that we are unique and this research is being used to help us to understand our human lineage, as well as giving us new insights into some diseases, such as cancer. The key to this discussion is a set of complex sugar chains (or carbohydrates), called glycans, which occur on the surface of cells. In particular, a glycan called Neu5Gc. It seems that at some point in the distant past, the malaria parasite used this glycan to anchor itself to the cells of primates and infect them with malaria, and human ancestors responded by losing the glycan, thus becoming immune to malaria. Unfortunately for us, a new type of malaria found a new glycan to attach itself to (this one is called Neu5Ac), which meant that humans could catch the new strain of malaria. This explains why humans are immune to the strains of malaria which affect great apes, such as chimpanzees, but are susceptible to strains of malaria which don’t affect the apes.

Humans became almost unique amongst mammals in not having the glycan Neu5Gc. It is thought that this mutation occurred between 2 and 3 million years ago and might have contributed to humans developing their own distinct lineage. Part of the glycan also becomes integrated as a molecule in bone, which gave researches hope that they might be able to find traces of the molecule from Neu5Gc in fossil bones. Whilst we have been successful in extracting ancient DNA from Neanderthal bones as old as 430,000 years and from horse bones as old as 700,000 years, fossils that are millions of years old have not been able to yield enough viable DNA using current techniques.

So researcher Ajit Varki, Distinguished Professor of Medicine and Cellular and Molecular Medicine at UC San Diego School of Medicine, started with 50,000 year old bones from a cave bear, from which they were able to extract the molecule. Varki then approached Maeve Leakey, Director of Field Research at the Turkana Basin Institute, who gave them a fragment of bone from a 4 million year old buffalo-like animal, found in the same layer as some hominin fossils. Once again the researchers were able to extract the molecule left in the bone by Nue5Gc. It is now hoped that they will be able to test fossil hominid bones in order to see which ones lacked Neu5Gc (and are thus likely to be our direct ancestors) and which ones had it.

Modern humans usually do have trace amounts of Neu5Gc, thought to enter our bodies from eating the meat of animals which have the glycan. Our bodies produce a slight immune response to the glycan, which might aggravate diseases such as cancer, opening new avenues for research and proving how research in one area of science, such as paleoanthropology, can have effects in other areas, such as medicine. It might therefore also be possible to see how much meat our ancestors included in their diets – always a controversial topic.

New Dates for Human Relative + ‘Explorer Classroom’ Resources

During September, National Geographic is featuring the excavations of Homo naledi at Rising Star Cave in South Africa in their Explorer Classroom, in tune with new discoveries and the publishing of dates for this enigmatic little hominid. A Teacher’s Guide and Resources are available and classes can log in to see live updates from the site. The material is also archived and can be watched via YouTube at a later date.

We’ve probably all heard of the little hominids from neighbouring Indonesia – Homo floresiensis and how they were initially dated to less than 50,000 years ago, which was then revised to between 60,000 and 190,000 years ago. These dates are still relatively recent for a hominid on the same general family tree as ourselves and reminds us all that there were several branches on this tree, of which ours is only one.

An interesting hominid was discovered in South Africa in 2014, named Homo naledi, this species was also relatively small and had a curious mix of features – some seeming very old (curved hands and fingers, well suited for climbing trees) and others looking more modern (legs suited to walking fully upright). Anthropologists and evolutionary biologists wondered where on the family tree these guys belonged – were they millions of years old, or more recent? The dating of the bones was an enormous challenge – partly because the deep cave where the fossils were found could only be accessed through an extremely narrow (20cm wide) gap in the rocks, and partly because the deposit lacked material that could be dated easily.

This year dates were published, obtained from a range of scientific techniques, including optically stimulated luminescence, Uranium-series and electron spin resonance dating (see OpenSTEM’s Absolute Dating Methods resource for explanations of some of these techniques). Both the sediments around the bones, as well as 3 fossil teeth were dated. The dates all clustered between 200,000 and 400,000 years ago. These dates are much more recent than was thought from analyses of the bones themselves. The dates are also contemporary with the very earliest of our own direct ancestors, implying that Homo naledi and our own ancestors shared the savannas of Africa hundreds of thousands of years ago. Yet another reminder of the diverse and complex nature of our family tree!

This Week in HASS – term 2, week 7

This week students are starting to round off their main body of assessable work for the term. Older students are completing and starting to present their presentations, while younger students have posters and models to finish off.

Foundation/Prep/Kindy to Year 3

Students in our stand-alone Foundation/Prep/Kindy unit (F.2) are continuing to explore with their senses this week. While still working on their model or collage for their Favourite Place, they are using their sense of Smell to consider which aromas they like or dislike. Teachers (and students) can bring in a range of things with different smells to explore in class. Ideas for these are given in the Teacher’s Handbook. An important part of this investigation is considering how one can represent one’s favourite smells in the model or collage – students might try to draw the objects associated with the smells, or see if they can find creative alternatives to represent this sense.

Students in integrated Foundation/Prep/Kindy and Year 1 classes (Unit F.6) and those in Years 1 (Unit 1.2), 2 (Unit 2.2) and 3 (Unit 3.2) are completing their posters to be displayed next week. These posters cover topics of local significance – either local history information, or dealing with issues, such as littering or the need for play equipment. As the students work on the posters, teachers are holding discussions with them on responsibility for different issues. The delegation of responsibility to members of the community, local government, other authorities, people who use the facilities, the school P&C, the students etc. should be discussed in class, so that students start to understand how people have different responsibilities in different situations. The teacher can also revisit issues of responsibility in the classroom – what are the students responsible for? What is the teacher responsible for? What is the school responsible for? These discussions are an important means of allowing the students to interact and practise group discussion skills, as well as helping them to think about responsibilities.

Years 3 to 6

Students in Year 3 (Unit 3.6) are completing their presentation on an extreme climate explorer and may start presenting it to the class this week. Year 4 students (Unit 4.2) are presenting on their explorer of Africa and South America. Year 5 students (Unit 5.2) are presenting on their chosen explorer from North America; and Year 6 students (Unit 6.2) are presenting on their chosen explorer from Asia. The remaining 3 weeks of this unit are allocated to the presentations, to ensure enough time for these to be given in full. The presentations should cover all the aspects raised over previous weeks and answered in the Student Workbook – the environments and geography of the areas explored; sustainability issues, such as extinction of animals and changes in local environments; characteristics of the countries involved in the explorations; reasons for explorations and how these created the background which led to the settlement of Australia and the role of indigenous people, as well as impact on indigenous people and their environments. The presentation is thus a comprehensive body of work.

This Week in HASS, term 2 week 5

NAPLAN’s over and it’s time to sink our teeth into the main body of curriculum work before mid-year reporting rolls around. Our younger students are using all their senses to study the environment and local area around them, whilst our older students are hard at work on their Explorer projects.

Foundation/Prep/Kindy to Year 3

Unit F.2 for stand-alone Foundation/Prep/Kindy classes has the students continuing to think about their Favourite Place. This week students are considering what they can hear in their Favourite Place and how they will depict that in their model of their Favourite Place. Students can also think about what their Favourite Sounds are and whether or not these would occur in their Favourite Place. Students in integrated Foundation/Prep/Kindy classes (Unit F.6) and Years 1 (Unit 1.2), 2 (Unit 2.2) and 3 (Unit 3.2) have this week set aside for an excursion to a local park or area of heritage significance. If an excursion outside school grounds is impractical teachers can achieve similar results from an excursion around the school and oval. Students are using their senses to interpret their environment, as well as thinking about living and non-living things, natural and managed landscapes and sources of heat and light.

Years 3 to 6

Students in Years 3 (Unit 3.6), 4 (Unit 4.2), 5 (Unit 5.2) and 6 (Unit 6.2) are continuing their project on an explorer. This week the focus for most students is on animals which may have been encountered by their explorer. Year 3 students are examining animals from different climate zones and how they are adapted to deal with climate extremes. Students in Years 4 and 5 look at extinct animals from Africa, South America or North America, assessing impact and sustainability issues. Students in Year 4 (and optionally as an extension for Year 3) consider the life cycle of their chosen animal. Students in years 4, 5 and 6 also start to examine the differences between Primary and Secondary sources and some of the OpenSTEM resources contain quotes or copies of primary material, so that students can refer to these in their project. Year 6 students are examining the changing Economies and Politics of Asia through time, in order to place the explorations within a broader context and to gain a greater understanding of the development of the global situation. Students have another 2 weeks to complete their presentation on their explorer (including environment and other aspects), before assessment of this project.

This Week in HASS – term 2, week 4

It’s NAPLAN week and that means time is short! Fortunately, the Understanding Our World™ program is based on 9 week units, which means that if you run out of time in any particular week, it’s not a disaster. Furthermore, we have made sure that there is plenty of catch-up time within the lessons, so that there is no need to feel rushed. This week students are getting into the nitty gritty of their term projects. Our youngest students are studying their surroundings at school and in the local area. Older students are getting to the core of their research projects.

Foundation to Year 3

Students in our standalone Foundation/Kindy/Prep class (unit F.2) are starting to build a model of their Favourite Place. It is the teacher’s choice whether they build a diorama, make a poster or collage, or how this is done in class. This week students start by drawing or cutting out pictures to show aspects of their favourite place. Students in an integrated Foundation/Kindy/Prep (unit F.6) and Year 1 class are using their senses to investigate their class and school – what can we see, hear, smell, feel and taste? Some ideas can be found in resources such as My Favourite Sounds and the Teacher Handbook also contains lots of ideas for these investigations. Students in Years 1 (unit 1.2), 2 (unit 2.2) and 3 (unit 3.2) are also discussing how the school and local area has changed through time. The teacher can use old maps, photos or newspaper reports to guide students through these discussions. What information is available in the school? What do local families remember?

Years 3 to 6

Students in Year 3 (unit 3.6), 4 (unit 4.2), 5 (unit 5.2) and 6 (unit 6.2) are continuing to research their explorer. This week year 3 students are focusing on the climates encountered by their explorer. Resources such as Climate Zones of Australia and Climate Zones of the World can help the class to identify these climate areas. Year 4 students examine Environments in Africa and South America, in order to discuss the environments encountered by their explorer. Students in Year 5 can read up about the environment encountered by their explorer in North America, and Year 6 students examine the Environments of Asia. In each case, the student workbook guides the student through this investigation and helps them to isolate pertinent information to include in their presentation. This helps students to gain an understanding of how to research a topic and derive an understanding of what information they need to consider. Teachers can use the workbook to check in and see how students are travelling in their progress towards completing the project, as well as their understanding of the content covered.

This Week in HASS – term 2, week 1

Welcome to the new school term, and we hope you all had a wonderful Easter! Many of our students are writing NAPLAN this term, so the HASS program provides a refreshing focus on something different, whilst practising skills that will help students prepare for NAPLAN without even realising it! Both literacy and numeracy are foundation skills of much of the broader curriculum and are reinforced within our HASS program as well. Meantime our younger students are focusing on local landscapes this term, while our older students are studying explorers of different continents.

Foundation to Year 3

Our youngest students (Foundation/Prep Unit F.2) start the term by looking at different types of homes. A wide selection of places can be homes for people around the world, so students can compare where they live to other types of homes. Students in integrated Foundation/Prep and Years 1 to 3 (Units F.6; 1.2; 2.2 and 3.2) start their examination of the local landscape by examining how Aboriginal people arrived in Australia 60,000 years ago. They learn how modern humans expanded across the world during the last Ice Age, reaching Australia via South-East Asia. Starting with this broad focus allows them to narrow down in later weeks, finally focusing on their local community.

Year 3 to Year 6

Students in Years 3 to 6 (Units 3.6; 4.2; 5.2 and 6.2) are looking at explorers this term. Each year level focuses on explorers of a different part of the world. Year 3 students investigate different climate zones and explorers of extreme climate areas (such as the Poles, or the Central Deserts of Australia). Year 4 students examine Africa and South America and investigate how European explorers during the ‘Age of Discovery‘ encountered different environments, animals and people on these continents. The students start with prehistory and this week they are looking at how Ancient Egyptians and Bantu-speaking groups explored Africa thousands of years ago. They also examine Great Zimbabwe. Year 5 students are studying North America, and this week are starting with the Viking voyages to Greenland and Newfoundland, in the 10th century. Year 6 students focus on Asia, and start with a study in Economics by examining the Dutch East India Company of the 17th and 18th centuries. (Remember HASS for years 5 and 6 includes History, Geography, Civics and Citizenship and Economics and Business – we cover it all, plus Science!)

You might be wondering how on earth we integrate such apparently disparate topics for multi-year classes! Well, our Teacher Handbooks are full of tricks to make teaching these integrated classes a breeze. The Teacher Handbooks with lesson plans and hints for how to integrate across year levels are included, along with the Student Workbooks, Model Answers and Assessment Guides, within our bundles for each unit. Teachers using these units have been thrilled at how easy it is to use our material in multi-year level classes, whilst knowing that each student is covering curriculum-appropriate material for their own year level.